1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * PACKET - implements raw packet sockets. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * 12 * Fixes: 13 * Alan Cox : verify_area() now used correctly 14 * Alan Cox : new skbuff lists, look ma no backlogs! 15 * Alan Cox : tidied skbuff lists. 16 * Alan Cox : Now uses generic datagram routines I 17 * added. Also fixed the peek/read crash 18 * from all old Linux datagram code. 19 * Alan Cox : Uses the improved datagram code. 20 * Alan Cox : Added NULL's for socket options. 21 * Alan Cox : Re-commented the code. 22 * Alan Cox : Use new kernel side addressing 23 * Rob Janssen : Correct MTU usage. 24 * Dave Platt : Counter leaks caused by incorrect 25 * interrupt locking and some slightly 26 * dubious gcc output. Can you read 27 * compiler: it said _VOLATILE_ 28 * Richard Kooijman : Timestamp fixes. 29 * Alan Cox : New buffers. Use sk->mac.raw. 30 * Alan Cox : sendmsg/recvmsg support. 31 * Alan Cox : Protocol setting support 32 * Alexey Kuznetsov : Untied from IPv4 stack. 33 * Cyrus Durgin : Fixed kerneld for kmod. 34 * Michal Ostrowski : Module initialization cleanup. 35 * Ulises Alonso : Frame number limit removal and 36 * packet_set_ring memory leak. 37 * Eric Biederman : Allow for > 8 byte hardware addresses. 38 * The convention is that longer addresses 39 * will simply extend the hardware address 40 * byte arrays at the end of sockaddr_ll 41 * and packet_mreq. 42 * Johann Baudy : Added TX RING. 43 * Chetan Loke : Implemented TPACKET_V3 block abstraction 44 * layer. 45 * Copyright (C) 2011, <lokec@ccs.neu.edu> 46 * 47 * 48 * This program is free software; you can redistribute it and/or 49 * modify it under the terms of the GNU General Public License 50 * as published by the Free Software Foundation; either version 51 * 2 of the License, or (at your option) any later version. 52 * 53 */ 54 55 #include <linux/types.h> 56 #include <linux/mm.h> 57 #include <linux/capability.h> 58 #include <linux/fcntl.h> 59 #include <linux/socket.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/if_packet.h> 64 #include <linux/wireless.h> 65 #include <linux/kernel.h> 66 #include <linux/kmod.h> 67 #include <linux/slab.h> 68 #include <linux/vmalloc.h> 69 #include <net/net_namespace.h> 70 #include <net/ip.h> 71 #include <net/protocol.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <linux/errno.h> 75 #include <linux/timer.h> 76 #include <linux/uaccess.h> 77 #include <asm/ioctls.h> 78 #include <asm/page.h> 79 #include <asm/cacheflush.h> 80 #include <asm/io.h> 81 #include <linux/proc_fs.h> 82 #include <linux/seq_file.h> 83 #include <linux/poll.h> 84 #include <linux/module.h> 85 #include <linux/init.h> 86 #include <linux/mutex.h> 87 #include <linux/if_vlan.h> 88 #include <linux/virtio_net.h> 89 #include <linux/errqueue.h> 90 #include <linux/net_tstamp.h> 91 #include <linux/percpu.h> 92 #ifdef CONFIG_INET 93 #include <net/inet_common.h> 94 #endif 95 #include <linux/bpf.h> 96 #include <net/compat.h> 97 98 #include "internal.h" 99 100 /* 101 Assumptions: 102 - if device has no dev->hard_header routine, it adds and removes ll header 103 inside itself. In this case ll header is invisible outside of device, 104 but higher levels still should reserve dev->hard_header_len. 105 Some devices are enough clever to reallocate skb, when header 106 will not fit to reserved space (tunnel), another ones are silly 107 (PPP). 108 - packet socket receives packets with pulled ll header, 109 so that SOCK_RAW should push it back. 110 111 On receive: 112 ----------- 113 114 Incoming, dev->hard_header!=NULL 115 mac_header -> ll header 116 data -> data 117 118 Outgoing, dev->hard_header!=NULL 119 mac_header -> ll header 120 data -> ll header 121 122 Incoming, dev->hard_header==NULL 123 mac_header -> UNKNOWN position. It is very likely, that it points to ll 124 header. PPP makes it, that is wrong, because introduce 125 assymetry between rx and tx paths. 126 data -> data 127 128 Outgoing, dev->hard_header==NULL 129 mac_header -> data. ll header is still not built! 130 data -> data 131 132 Resume 133 If dev->hard_header==NULL we are unlikely to restore sensible ll header. 134 135 136 On transmit: 137 ------------ 138 139 dev->hard_header != NULL 140 mac_header -> ll header 141 data -> ll header 142 143 dev->hard_header == NULL (ll header is added by device, we cannot control it) 144 mac_header -> data 145 data -> data 146 147 We should set nh.raw on output to correct posistion, 148 packet classifier depends on it. 149 */ 150 151 /* Private packet socket structures. */ 152 153 /* identical to struct packet_mreq except it has 154 * a longer address field. 155 */ 156 struct packet_mreq_max { 157 int mr_ifindex; 158 unsigned short mr_type; 159 unsigned short mr_alen; 160 unsigned char mr_address[MAX_ADDR_LEN]; 161 }; 162 163 union tpacket_uhdr { 164 struct tpacket_hdr *h1; 165 struct tpacket2_hdr *h2; 166 struct tpacket3_hdr *h3; 167 void *raw; 168 }; 169 170 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 171 int closing, int tx_ring); 172 173 #define V3_ALIGNMENT (8) 174 175 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) 176 177 #define BLK_PLUS_PRIV(sz_of_priv) \ 178 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) 179 180 #define PGV_FROM_VMALLOC 1 181 182 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) 183 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) 184 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) 185 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) 186 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) 187 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv) 188 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x))) 189 190 struct packet_sock; 191 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg); 192 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 193 struct packet_type *pt, struct net_device *orig_dev); 194 195 static void *packet_previous_frame(struct packet_sock *po, 196 struct packet_ring_buffer *rb, 197 int status); 198 static void packet_increment_head(struct packet_ring_buffer *buff); 199 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *, 200 struct tpacket_block_desc *); 201 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, 202 struct packet_sock *); 203 static void prb_retire_current_block(struct tpacket_kbdq_core *, 204 struct packet_sock *, unsigned int status); 205 static int prb_queue_frozen(struct tpacket_kbdq_core *); 206 static void prb_open_block(struct tpacket_kbdq_core *, 207 struct tpacket_block_desc *); 208 static void prb_retire_rx_blk_timer_expired(unsigned long); 209 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); 210 static void prb_init_blk_timer(struct packet_sock *, 211 struct tpacket_kbdq_core *, 212 void (*func) (unsigned long)); 213 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); 214 static void prb_clear_rxhash(struct tpacket_kbdq_core *, 215 struct tpacket3_hdr *); 216 static void prb_fill_vlan_info(struct tpacket_kbdq_core *, 217 struct tpacket3_hdr *); 218 static void packet_flush_mclist(struct sock *sk); 219 220 struct packet_skb_cb { 221 union { 222 struct sockaddr_pkt pkt; 223 union { 224 /* Trick: alias skb original length with 225 * ll.sll_family and ll.protocol in order 226 * to save room. 227 */ 228 unsigned int origlen; 229 struct sockaddr_ll ll; 230 }; 231 } sa; 232 }; 233 234 #define vio_le() virtio_legacy_is_little_endian() 235 236 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) 237 238 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) 239 #define GET_PBLOCK_DESC(x, bid) \ 240 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) 241 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ 242 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) 243 #define GET_NEXT_PRB_BLK_NUM(x) \ 244 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ 245 ((x)->kactive_blk_num+1) : 0) 246 247 static void __fanout_unlink(struct sock *sk, struct packet_sock *po); 248 static void __fanout_link(struct sock *sk, struct packet_sock *po); 249 250 static int packet_direct_xmit(struct sk_buff *skb) 251 { 252 struct net_device *dev = skb->dev; 253 struct sk_buff *orig_skb = skb; 254 struct netdev_queue *txq; 255 int ret = NETDEV_TX_BUSY; 256 257 if (unlikely(!netif_running(dev) || 258 !netif_carrier_ok(dev))) 259 goto drop; 260 261 skb = validate_xmit_skb_list(skb, dev); 262 if (skb != orig_skb) 263 goto drop; 264 265 txq = skb_get_tx_queue(dev, skb); 266 267 local_bh_disable(); 268 269 HARD_TX_LOCK(dev, txq, smp_processor_id()); 270 if (!netif_xmit_frozen_or_drv_stopped(txq)) 271 ret = netdev_start_xmit(skb, dev, txq, false); 272 HARD_TX_UNLOCK(dev, txq); 273 274 local_bh_enable(); 275 276 if (!dev_xmit_complete(ret)) 277 kfree_skb(skb); 278 279 return ret; 280 drop: 281 atomic_long_inc(&dev->tx_dropped); 282 kfree_skb_list(skb); 283 return NET_XMIT_DROP; 284 } 285 286 static struct net_device *packet_cached_dev_get(struct packet_sock *po) 287 { 288 struct net_device *dev; 289 290 rcu_read_lock(); 291 dev = rcu_dereference(po->cached_dev); 292 if (likely(dev)) 293 dev_hold(dev); 294 rcu_read_unlock(); 295 296 return dev; 297 } 298 299 static void packet_cached_dev_assign(struct packet_sock *po, 300 struct net_device *dev) 301 { 302 rcu_assign_pointer(po->cached_dev, dev); 303 } 304 305 static void packet_cached_dev_reset(struct packet_sock *po) 306 { 307 RCU_INIT_POINTER(po->cached_dev, NULL); 308 } 309 310 static bool packet_use_direct_xmit(const struct packet_sock *po) 311 { 312 return po->xmit == packet_direct_xmit; 313 } 314 315 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 316 { 317 return (u16) raw_smp_processor_id() % dev->real_num_tx_queues; 318 } 319 320 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb) 321 { 322 const struct net_device_ops *ops = dev->netdev_ops; 323 u16 queue_index; 324 325 if (ops->ndo_select_queue) { 326 queue_index = ops->ndo_select_queue(dev, skb, NULL, 327 __packet_pick_tx_queue); 328 queue_index = netdev_cap_txqueue(dev, queue_index); 329 } else { 330 queue_index = __packet_pick_tx_queue(dev, skb); 331 } 332 333 skb_set_queue_mapping(skb, queue_index); 334 } 335 336 /* register_prot_hook must be invoked with the po->bind_lock held, 337 * or from a context in which asynchronous accesses to the packet 338 * socket is not possible (packet_create()). 339 */ 340 static void register_prot_hook(struct sock *sk) 341 { 342 struct packet_sock *po = pkt_sk(sk); 343 344 if (!po->running) { 345 if (po->fanout) 346 __fanout_link(sk, po); 347 else 348 dev_add_pack(&po->prot_hook); 349 350 sock_hold(sk); 351 po->running = 1; 352 } 353 } 354 355 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock 356 * held. If the sync parameter is true, we will temporarily drop 357 * the po->bind_lock and do a synchronize_net to make sure no 358 * asynchronous packet processing paths still refer to the elements 359 * of po->prot_hook. If the sync parameter is false, it is the 360 * callers responsibility to take care of this. 361 */ 362 static void __unregister_prot_hook(struct sock *sk, bool sync) 363 { 364 struct packet_sock *po = pkt_sk(sk); 365 366 po->running = 0; 367 368 if (po->fanout) 369 __fanout_unlink(sk, po); 370 else 371 __dev_remove_pack(&po->prot_hook); 372 373 __sock_put(sk); 374 375 if (sync) { 376 spin_unlock(&po->bind_lock); 377 synchronize_net(); 378 spin_lock(&po->bind_lock); 379 } 380 } 381 382 static void unregister_prot_hook(struct sock *sk, bool sync) 383 { 384 struct packet_sock *po = pkt_sk(sk); 385 386 if (po->running) 387 __unregister_prot_hook(sk, sync); 388 } 389 390 static inline struct page * __pure pgv_to_page(void *addr) 391 { 392 if (is_vmalloc_addr(addr)) 393 return vmalloc_to_page(addr); 394 return virt_to_page(addr); 395 } 396 397 static void __packet_set_status(struct packet_sock *po, void *frame, int status) 398 { 399 union tpacket_uhdr h; 400 401 h.raw = frame; 402 switch (po->tp_version) { 403 case TPACKET_V1: 404 h.h1->tp_status = status; 405 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 406 break; 407 case TPACKET_V2: 408 h.h2->tp_status = status; 409 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 410 break; 411 case TPACKET_V3: 412 h.h3->tp_status = status; 413 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 414 break; 415 default: 416 WARN(1, "TPACKET version not supported.\n"); 417 BUG(); 418 } 419 420 smp_wmb(); 421 } 422 423 static int __packet_get_status(struct packet_sock *po, void *frame) 424 { 425 union tpacket_uhdr h; 426 427 smp_rmb(); 428 429 h.raw = frame; 430 switch (po->tp_version) { 431 case TPACKET_V1: 432 flush_dcache_page(pgv_to_page(&h.h1->tp_status)); 433 return h.h1->tp_status; 434 case TPACKET_V2: 435 flush_dcache_page(pgv_to_page(&h.h2->tp_status)); 436 return h.h2->tp_status; 437 case TPACKET_V3: 438 flush_dcache_page(pgv_to_page(&h.h3->tp_status)); 439 return h.h3->tp_status; 440 default: 441 WARN(1, "TPACKET version not supported.\n"); 442 BUG(); 443 return 0; 444 } 445 } 446 447 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts, 448 unsigned int flags) 449 { 450 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); 451 452 if (shhwtstamps && 453 (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && 454 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts)) 455 return TP_STATUS_TS_RAW_HARDWARE; 456 457 if (ktime_to_timespec_cond(skb->tstamp, ts)) 458 return TP_STATUS_TS_SOFTWARE; 459 460 return 0; 461 } 462 463 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, 464 struct sk_buff *skb) 465 { 466 union tpacket_uhdr h; 467 struct timespec ts; 468 __u32 ts_status; 469 470 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 471 return 0; 472 473 h.raw = frame; 474 switch (po->tp_version) { 475 case TPACKET_V1: 476 h.h1->tp_sec = ts.tv_sec; 477 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 478 break; 479 case TPACKET_V2: 480 h.h2->tp_sec = ts.tv_sec; 481 h.h2->tp_nsec = ts.tv_nsec; 482 break; 483 case TPACKET_V3: 484 h.h3->tp_sec = ts.tv_sec; 485 h.h3->tp_nsec = ts.tv_nsec; 486 break; 487 default: 488 WARN(1, "TPACKET version not supported.\n"); 489 BUG(); 490 } 491 492 /* one flush is safe, as both fields always lie on the same cacheline */ 493 flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); 494 smp_wmb(); 495 496 return ts_status; 497 } 498 499 static void *packet_lookup_frame(struct packet_sock *po, 500 struct packet_ring_buffer *rb, 501 unsigned int position, 502 int status) 503 { 504 unsigned int pg_vec_pos, frame_offset; 505 union tpacket_uhdr h; 506 507 pg_vec_pos = position / rb->frames_per_block; 508 frame_offset = position % rb->frames_per_block; 509 510 h.raw = rb->pg_vec[pg_vec_pos].buffer + 511 (frame_offset * rb->frame_size); 512 513 if (status != __packet_get_status(po, h.raw)) 514 return NULL; 515 516 return h.raw; 517 } 518 519 static void *packet_current_frame(struct packet_sock *po, 520 struct packet_ring_buffer *rb, 521 int status) 522 { 523 return packet_lookup_frame(po, rb, rb->head, status); 524 } 525 526 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) 527 { 528 del_timer_sync(&pkc->retire_blk_timer); 529 } 530 531 static void prb_shutdown_retire_blk_timer(struct packet_sock *po, 532 struct sk_buff_head *rb_queue) 533 { 534 struct tpacket_kbdq_core *pkc; 535 536 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 537 538 spin_lock_bh(&rb_queue->lock); 539 pkc->delete_blk_timer = 1; 540 spin_unlock_bh(&rb_queue->lock); 541 542 prb_del_retire_blk_timer(pkc); 543 } 544 545 static void prb_init_blk_timer(struct packet_sock *po, 546 struct tpacket_kbdq_core *pkc, 547 void (*func) (unsigned long)) 548 { 549 init_timer(&pkc->retire_blk_timer); 550 pkc->retire_blk_timer.data = (long)po; 551 pkc->retire_blk_timer.function = func; 552 pkc->retire_blk_timer.expires = jiffies; 553 } 554 555 static void prb_setup_retire_blk_timer(struct packet_sock *po) 556 { 557 struct tpacket_kbdq_core *pkc; 558 559 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 560 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired); 561 } 562 563 static int prb_calc_retire_blk_tmo(struct packet_sock *po, 564 int blk_size_in_bytes) 565 { 566 struct net_device *dev; 567 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0; 568 struct ethtool_link_ksettings ecmd; 569 int err; 570 571 rtnl_lock(); 572 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); 573 if (unlikely(!dev)) { 574 rtnl_unlock(); 575 return DEFAULT_PRB_RETIRE_TOV; 576 } 577 err = __ethtool_get_link_ksettings(dev, &ecmd); 578 rtnl_unlock(); 579 if (!err) { 580 /* 581 * If the link speed is so slow you don't really 582 * need to worry about perf anyways 583 */ 584 if (ecmd.base.speed < SPEED_1000 || 585 ecmd.base.speed == SPEED_UNKNOWN) { 586 return DEFAULT_PRB_RETIRE_TOV; 587 } else { 588 msec = 1; 589 div = ecmd.base.speed / 1000; 590 } 591 } 592 593 mbits = (blk_size_in_bytes * 8) / (1024 * 1024); 594 595 if (div) 596 mbits /= div; 597 598 tmo = mbits * msec; 599 600 if (div) 601 return tmo+1; 602 return tmo; 603 } 604 605 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, 606 union tpacket_req_u *req_u) 607 { 608 p1->feature_req_word = req_u->req3.tp_feature_req_word; 609 } 610 611 static void init_prb_bdqc(struct packet_sock *po, 612 struct packet_ring_buffer *rb, 613 struct pgv *pg_vec, 614 union tpacket_req_u *req_u) 615 { 616 struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); 617 struct tpacket_block_desc *pbd; 618 619 memset(p1, 0x0, sizeof(*p1)); 620 621 p1->knxt_seq_num = 1; 622 p1->pkbdq = pg_vec; 623 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; 624 p1->pkblk_start = pg_vec[0].buffer; 625 p1->kblk_size = req_u->req3.tp_block_size; 626 p1->knum_blocks = req_u->req3.tp_block_nr; 627 p1->hdrlen = po->tp_hdrlen; 628 p1->version = po->tp_version; 629 p1->last_kactive_blk_num = 0; 630 po->stats.stats3.tp_freeze_q_cnt = 0; 631 if (req_u->req3.tp_retire_blk_tov) 632 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; 633 else 634 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, 635 req_u->req3.tp_block_size); 636 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); 637 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; 638 639 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); 640 prb_init_ft_ops(p1, req_u); 641 prb_setup_retire_blk_timer(po); 642 prb_open_block(p1, pbd); 643 } 644 645 /* Do NOT update the last_blk_num first. 646 * Assumes sk_buff_head lock is held. 647 */ 648 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) 649 { 650 mod_timer(&pkc->retire_blk_timer, 651 jiffies + pkc->tov_in_jiffies); 652 pkc->last_kactive_blk_num = pkc->kactive_blk_num; 653 } 654 655 /* 656 * Timer logic: 657 * 1) We refresh the timer only when we open a block. 658 * By doing this we don't waste cycles refreshing the timer 659 * on packet-by-packet basis. 660 * 661 * With a 1MB block-size, on a 1Gbps line, it will take 662 * i) ~8 ms to fill a block + ii) memcpy etc. 663 * In this cut we are not accounting for the memcpy time. 664 * 665 * So, if the user sets the 'tmo' to 10ms then the timer 666 * will never fire while the block is still getting filled 667 * (which is what we want). However, the user could choose 668 * to close a block early and that's fine. 669 * 670 * But when the timer does fire, we check whether or not to refresh it. 671 * Since the tmo granularity is in msecs, it is not too expensive 672 * to refresh the timer, lets say every '8' msecs. 673 * Either the user can set the 'tmo' or we can derive it based on 674 * a) line-speed and b) block-size. 675 * prb_calc_retire_blk_tmo() calculates the tmo. 676 * 677 */ 678 static void prb_retire_rx_blk_timer_expired(unsigned long data) 679 { 680 struct packet_sock *po = (struct packet_sock *)data; 681 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 682 unsigned int frozen; 683 struct tpacket_block_desc *pbd; 684 685 spin_lock(&po->sk.sk_receive_queue.lock); 686 687 frozen = prb_queue_frozen(pkc); 688 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 689 690 if (unlikely(pkc->delete_blk_timer)) 691 goto out; 692 693 /* We only need to plug the race when the block is partially filled. 694 * tpacket_rcv: 695 * lock(); increment BLOCK_NUM_PKTS; unlock() 696 * copy_bits() is in progress ... 697 * timer fires on other cpu: 698 * we can't retire the current block because copy_bits 699 * is in progress. 700 * 701 */ 702 if (BLOCK_NUM_PKTS(pbd)) { 703 while (atomic_read(&pkc->blk_fill_in_prog)) { 704 /* Waiting for skb_copy_bits to finish... */ 705 cpu_relax(); 706 } 707 } 708 709 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { 710 if (!frozen) { 711 if (!BLOCK_NUM_PKTS(pbd)) { 712 /* An empty block. Just refresh the timer. */ 713 goto refresh_timer; 714 } 715 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); 716 if (!prb_dispatch_next_block(pkc, po)) 717 goto refresh_timer; 718 else 719 goto out; 720 } else { 721 /* Case 1. Queue was frozen because user-space was 722 * lagging behind. 723 */ 724 if (prb_curr_blk_in_use(pkc, pbd)) { 725 /* 726 * Ok, user-space is still behind. 727 * So just refresh the timer. 728 */ 729 goto refresh_timer; 730 } else { 731 /* Case 2. queue was frozen,user-space caught up, 732 * now the link went idle && the timer fired. 733 * We don't have a block to close.So we open this 734 * block and restart the timer. 735 * opening a block thaws the queue,restarts timer 736 * Thawing/timer-refresh is a side effect. 737 */ 738 prb_open_block(pkc, pbd); 739 goto out; 740 } 741 } 742 } 743 744 refresh_timer: 745 _prb_refresh_rx_retire_blk_timer(pkc); 746 747 out: 748 spin_unlock(&po->sk.sk_receive_queue.lock); 749 } 750 751 static void prb_flush_block(struct tpacket_kbdq_core *pkc1, 752 struct tpacket_block_desc *pbd1, __u32 status) 753 { 754 /* Flush everything minus the block header */ 755 756 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 757 u8 *start, *end; 758 759 start = (u8 *)pbd1; 760 761 /* Skip the block header(we know header WILL fit in 4K) */ 762 start += PAGE_SIZE; 763 764 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); 765 for (; start < end; start += PAGE_SIZE) 766 flush_dcache_page(pgv_to_page(start)); 767 768 smp_wmb(); 769 #endif 770 771 /* Now update the block status. */ 772 773 BLOCK_STATUS(pbd1) = status; 774 775 /* Flush the block header */ 776 777 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 778 start = (u8 *)pbd1; 779 flush_dcache_page(pgv_to_page(start)); 780 781 smp_wmb(); 782 #endif 783 } 784 785 /* 786 * Side effect: 787 * 788 * 1) flush the block 789 * 2) Increment active_blk_num 790 * 791 * Note:We DONT refresh the timer on purpose. 792 * Because almost always the next block will be opened. 793 */ 794 static void prb_close_block(struct tpacket_kbdq_core *pkc1, 795 struct tpacket_block_desc *pbd1, 796 struct packet_sock *po, unsigned int stat) 797 { 798 __u32 status = TP_STATUS_USER | stat; 799 800 struct tpacket3_hdr *last_pkt; 801 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 802 struct sock *sk = &po->sk; 803 804 if (po->stats.stats3.tp_drops) 805 status |= TP_STATUS_LOSING; 806 807 last_pkt = (struct tpacket3_hdr *)pkc1->prev; 808 last_pkt->tp_next_offset = 0; 809 810 /* Get the ts of the last pkt */ 811 if (BLOCK_NUM_PKTS(pbd1)) { 812 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; 813 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; 814 } else { 815 /* Ok, we tmo'd - so get the current time. 816 * 817 * It shouldn't really happen as we don't close empty 818 * blocks. See prb_retire_rx_blk_timer_expired(). 819 */ 820 struct timespec ts; 821 getnstimeofday(&ts); 822 h1->ts_last_pkt.ts_sec = ts.tv_sec; 823 h1->ts_last_pkt.ts_nsec = ts.tv_nsec; 824 } 825 826 smp_wmb(); 827 828 /* Flush the block */ 829 prb_flush_block(pkc1, pbd1, status); 830 831 sk->sk_data_ready(sk); 832 833 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); 834 } 835 836 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) 837 { 838 pkc->reset_pending_on_curr_blk = 0; 839 } 840 841 /* 842 * Side effect of opening a block: 843 * 844 * 1) prb_queue is thawed. 845 * 2) retire_blk_timer is refreshed. 846 * 847 */ 848 static void prb_open_block(struct tpacket_kbdq_core *pkc1, 849 struct tpacket_block_desc *pbd1) 850 { 851 struct timespec ts; 852 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; 853 854 smp_rmb(); 855 856 /* We could have just memset this but we will lose the 857 * flexibility of making the priv area sticky 858 */ 859 860 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; 861 BLOCK_NUM_PKTS(pbd1) = 0; 862 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 863 864 getnstimeofday(&ts); 865 866 h1->ts_first_pkt.ts_sec = ts.tv_sec; 867 h1->ts_first_pkt.ts_nsec = ts.tv_nsec; 868 869 pkc1->pkblk_start = (char *)pbd1; 870 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 871 872 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); 873 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; 874 875 pbd1->version = pkc1->version; 876 pkc1->prev = pkc1->nxt_offset; 877 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; 878 879 prb_thaw_queue(pkc1); 880 _prb_refresh_rx_retire_blk_timer(pkc1); 881 882 smp_wmb(); 883 } 884 885 /* 886 * Queue freeze logic: 887 * 1) Assume tp_block_nr = 8 blocks. 888 * 2) At time 't0', user opens Rx ring. 889 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 890 * 4) user-space is either sleeping or processing block '0'. 891 * 5) tpacket_rcv is currently filling block '7', since there is no space left, 892 * it will close block-7,loop around and try to fill block '0'. 893 * call-flow: 894 * __packet_lookup_frame_in_block 895 * prb_retire_current_block() 896 * prb_dispatch_next_block() 897 * |->(BLOCK_STATUS == USER) evaluates to true 898 * 5.1) Since block-0 is currently in-use, we just freeze the queue. 899 * 6) Now there are two cases: 900 * 6.1) Link goes idle right after the queue is frozen. 901 * But remember, the last open_block() refreshed the timer. 902 * When this timer expires,it will refresh itself so that we can 903 * re-open block-0 in near future. 904 * 6.2) Link is busy and keeps on receiving packets. This is a simple 905 * case and __packet_lookup_frame_in_block will check if block-0 906 * is free and can now be re-used. 907 */ 908 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 909 struct packet_sock *po) 910 { 911 pkc->reset_pending_on_curr_blk = 1; 912 po->stats.stats3.tp_freeze_q_cnt++; 913 } 914 915 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) 916 917 /* 918 * If the next block is free then we will dispatch it 919 * and return a good offset. 920 * Else, we will freeze the queue. 921 * So, caller must check the return value. 922 */ 923 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, 924 struct packet_sock *po) 925 { 926 struct tpacket_block_desc *pbd; 927 928 smp_rmb(); 929 930 /* 1. Get current block num */ 931 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 932 933 /* 2. If this block is currently in_use then freeze the queue */ 934 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { 935 prb_freeze_queue(pkc, po); 936 return NULL; 937 } 938 939 /* 940 * 3. 941 * open this block and return the offset where the first packet 942 * needs to get stored. 943 */ 944 prb_open_block(pkc, pbd); 945 return (void *)pkc->nxt_offset; 946 } 947 948 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, 949 struct packet_sock *po, unsigned int status) 950 { 951 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 952 953 /* retire/close the current block */ 954 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { 955 /* 956 * Plug the case where copy_bits() is in progress on 957 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't 958 * have space to copy the pkt in the current block and 959 * called prb_retire_current_block() 960 * 961 * We don't need to worry about the TMO case because 962 * the timer-handler already handled this case. 963 */ 964 if (!(status & TP_STATUS_BLK_TMO)) { 965 while (atomic_read(&pkc->blk_fill_in_prog)) { 966 /* Waiting for skb_copy_bits to finish... */ 967 cpu_relax(); 968 } 969 } 970 prb_close_block(pkc, pbd, po, status); 971 return; 972 } 973 } 974 975 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc, 976 struct tpacket_block_desc *pbd) 977 { 978 return TP_STATUS_USER & BLOCK_STATUS(pbd); 979 } 980 981 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) 982 { 983 return pkc->reset_pending_on_curr_blk; 984 } 985 986 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) 987 { 988 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 989 atomic_dec(&pkc->blk_fill_in_prog); 990 } 991 992 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, 993 struct tpacket3_hdr *ppd) 994 { 995 ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); 996 } 997 998 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, 999 struct tpacket3_hdr *ppd) 1000 { 1001 ppd->hv1.tp_rxhash = 0; 1002 } 1003 1004 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, 1005 struct tpacket3_hdr *ppd) 1006 { 1007 if (skb_vlan_tag_present(pkc->skb)) { 1008 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); 1009 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); 1010 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 1011 } else { 1012 ppd->hv1.tp_vlan_tci = 0; 1013 ppd->hv1.tp_vlan_tpid = 0; 1014 ppd->tp_status = TP_STATUS_AVAILABLE; 1015 } 1016 } 1017 1018 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, 1019 struct tpacket3_hdr *ppd) 1020 { 1021 ppd->hv1.tp_padding = 0; 1022 prb_fill_vlan_info(pkc, ppd); 1023 1024 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) 1025 prb_fill_rxhash(pkc, ppd); 1026 else 1027 prb_clear_rxhash(pkc, ppd); 1028 } 1029 1030 static void prb_fill_curr_block(char *curr, 1031 struct tpacket_kbdq_core *pkc, 1032 struct tpacket_block_desc *pbd, 1033 unsigned int len) 1034 { 1035 struct tpacket3_hdr *ppd; 1036 1037 ppd = (struct tpacket3_hdr *)curr; 1038 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); 1039 pkc->prev = curr; 1040 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); 1041 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); 1042 BLOCK_NUM_PKTS(pbd) += 1; 1043 atomic_inc(&pkc->blk_fill_in_prog); 1044 prb_run_all_ft_ops(pkc, ppd); 1045 } 1046 1047 /* Assumes caller has the sk->rx_queue.lock */ 1048 static void *__packet_lookup_frame_in_block(struct packet_sock *po, 1049 struct sk_buff *skb, 1050 int status, 1051 unsigned int len 1052 ) 1053 { 1054 struct tpacket_kbdq_core *pkc; 1055 struct tpacket_block_desc *pbd; 1056 char *curr, *end; 1057 1058 pkc = GET_PBDQC_FROM_RB(&po->rx_ring); 1059 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1060 1061 /* Queue is frozen when user space is lagging behind */ 1062 if (prb_queue_frozen(pkc)) { 1063 /* 1064 * Check if that last block which caused the queue to freeze, 1065 * is still in_use by user-space. 1066 */ 1067 if (prb_curr_blk_in_use(pkc, pbd)) { 1068 /* Can't record this packet */ 1069 return NULL; 1070 } else { 1071 /* 1072 * Ok, the block was released by user-space. 1073 * Now let's open that block. 1074 * opening a block also thaws the queue. 1075 * Thawing is a side effect. 1076 */ 1077 prb_open_block(pkc, pbd); 1078 } 1079 } 1080 1081 smp_mb(); 1082 curr = pkc->nxt_offset; 1083 pkc->skb = skb; 1084 end = (char *)pbd + pkc->kblk_size; 1085 1086 /* first try the current block */ 1087 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { 1088 prb_fill_curr_block(curr, pkc, pbd, len); 1089 return (void *)curr; 1090 } 1091 1092 /* Ok, close the current block */ 1093 prb_retire_current_block(pkc, po, 0); 1094 1095 /* Now, try to dispatch the next block */ 1096 curr = (char *)prb_dispatch_next_block(pkc, po); 1097 if (curr) { 1098 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); 1099 prb_fill_curr_block(curr, pkc, pbd, len); 1100 return (void *)curr; 1101 } 1102 1103 /* 1104 * No free blocks are available.user_space hasn't caught up yet. 1105 * Queue was just frozen and now this packet will get dropped. 1106 */ 1107 return NULL; 1108 } 1109 1110 static void *packet_current_rx_frame(struct packet_sock *po, 1111 struct sk_buff *skb, 1112 int status, unsigned int len) 1113 { 1114 char *curr = NULL; 1115 switch (po->tp_version) { 1116 case TPACKET_V1: 1117 case TPACKET_V2: 1118 curr = packet_lookup_frame(po, &po->rx_ring, 1119 po->rx_ring.head, status); 1120 return curr; 1121 case TPACKET_V3: 1122 return __packet_lookup_frame_in_block(po, skb, status, len); 1123 default: 1124 WARN(1, "TPACKET version not supported\n"); 1125 BUG(); 1126 return NULL; 1127 } 1128 } 1129 1130 static void *prb_lookup_block(struct packet_sock *po, 1131 struct packet_ring_buffer *rb, 1132 unsigned int idx, 1133 int status) 1134 { 1135 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); 1136 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); 1137 1138 if (status != BLOCK_STATUS(pbd)) 1139 return NULL; 1140 return pbd; 1141 } 1142 1143 static int prb_previous_blk_num(struct packet_ring_buffer *rb) 1144 { 1145 unsigned int prev; 1146 if (rb->prb_bdqc.kactive_blk_num) 1147 prev = rb->prb_bdqc.kactive_blk_num-1; 1148 else 1149 prev = rb->prb_bdqc.knum_blocks-1; 1150 return prev; 1151 } 1152 1153 /* Assumes caller has held the rx_queue.lock */ 1154 static void *__prb_previous_block(struct packet_sock *po, 1155 struct packet_ring_buffer *rb, 1156 int status) 1157 { 1158 unsigned int previous = prb_previous_blk_num(rb); 1159 return prb_lookup_block(po, rb, previous, status); 1160 } 1161 1162 static void *packet_previous_rx_frame(struct packet_sock *po, 1163 struct packet_ring_buffer *rb, 1164 int status) 1165 { 1166 if (po->tp_version <= TPACKET_V2) 1167 return packet_previous_frame(po, rb, status); 1168 1169 return __prb_previous_block(po, rb, status); 1170 } 1171 1172 static void packet_increment_rx_head(struct packet_sock *po, 1173 struct packet_ring_buffer *rb) 1174 { 1175 switch (po->tp_version) { 1176 case TPACKET_V1: 1177 case TPACKET_V2: 1178 return packet_increment_head(rb); 1179 case TPACKET_V3: 1180 default: 1181 WARN(1, "TPACKET version not supported.\n"); 1182 BUG(); 1183 return; 1184 } 1185 } 1186 1187 static void *packet_previous_frame(struct packet_sock *po, 1188 struct packet_ring_buffer *rb, 1189 int status) 1190 { 1191 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; 1192 return packet_lookup_frame(po, rb, previous, status); 1193 } 1194 1195 static void packet_increment_head(struct packet_ring_buffer *buff) 1196 { 1197 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; 1198 } 1199 1200 static void packet_inc_pending(struct packet_ring_buffer *rb) 1201 { 1202 this_cpu_inc(*rb->pending_refcnt); 1203 } 1204 1205 static void packet_dec_pending(struct packet_ring_buffer *rb) 1206 { 1207 this_cpu_dec(*rb->pending_refcnt); 1208 } 1209 1210 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) 1211 { 1212 unsigned int refcnt = 0; 1213 int cpu; 1214 1215 /* We don't use pending refcount in rx_ring. */ 1216 if (rb->pending_refcnt == NULL) 1217 return 0; 1218 1219 for_each_possible_cpu(cpu) 1220 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); 1221 1222 return refcnt; 1223 } 1224 1225 static int packet_alloc_pending(struct packet_sock *po) 1226 { 1227 po->rx_ring.pending_refcnt = NULL; 1228 1229 po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); 1230 if (unlikely(po->tx_ring.pending_refcnt == NULL)) 1231 return -ENOBUFS; 1232 1233 return 0; 1234 } 1235 1236 static void packet_free_pending(struct packet_sock *po) 1237 { 1238 free_percpu(po->tx_ring.pending_refcnt); 1239 } 1240 1241 #define ROOM_POW_OFF 2 1242 #define ROOM_NONE 0x0 1243 #define ROOM_LOW 0x1 1244 #define ROOM_NORMAL 0x2 1245 1246 static bool __tpacket_has_room(struct packet_sock *po, int pow_off) 1247 { 1248 int idx, len; 1249 1250 len = po->rx_ring.frame_max + 1; 1251 idx = po->rx_ring.head; 1252 if (pow_off) 1253 idx += len >> pow_off; 1254 if (idx >= len) 1255 idx -= len; 1256 return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1257 } 1258 1259 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off) 1260 { 1261 int idx, len; 1262 1263 len = po->rx_ring.prb_bdqc.knum_blocks; 1264 idx = po->rx_ring.prb_bdqc.kactive_blk_num; 1265 if (pow_off) 1266 idx += len >> pow_off; 1267 if (idx >= len) 1268 idx -= len; 1269 return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); 1270 } 1271 1272 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1273 { 1274 struct sock *sk = &po->sk; 1275 int ret = ROOM_NONE; 1276 1277 if (po->prot_hook.func != tpacket_rcv) { 1278 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc) 1279 - (skb ? skb->truesize : 0); 1280 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF)) 1281 return ROOM_NORMAL; 1282 else if (avail > 0) 1283 return ROOM_LOW; 1284 else 1285 return ROOM_NONE; 1286 } 1287 1288 if (po->tp_version == TPACKET_V3) { 1289 if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) 1290 ret = ROOM_NORMAL; 1291 else if (__tpacket_v3_has_room(po, 0)) 1292 ret = ROOM_LOW; 1293 } else { 1294 if (__tpacket_has_room(po, ROOM_POW_OFF)) 1295 ret = ROOM_NORMAL; 1296 else if (__tpacket_has_room(po, 0)) 1297 ret = ROOM_LOW; 1298 } 1299 1300 return ret; 1301 } 1302 1303 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) 1304 { 1305 int ret; 1306 bool has_room; 1307 1308 spin_lock_bh(&po->sk.sk_receive_queue.lock); 1309 ret = __packet_rcv_has_room(po, skb); 1310 has_room = ret == ROOM_NORMAL; 1311 if (po->pressure == has_room) 1312 po->pressure = !has_room; 1313 spin_unlock_bh(&po->sk.sk_receive_queue.lock); 1314 1315 return ret; 1316 } 1317 1318 static void packet_sock_destruct(struct sock *sk) 1319 { 1320 skb_queue_purge(&sk->sk_error_queue); 1321 1322 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 1323 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 1324 1325 if (!sock_flag(sk, SOCK_DEAD)) { 1326 pr_err("Attempt to release alive packet socket: %p\n", sk); 1327 return; 1328 } 1329 1330 sk_refcnt_debug_dec(sk); 1331 } 1332 1333 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) 1334 { 1335 u32 rxhash; 1336 int i, count = 0; 1337 1338 rxhash = skb_get_hash(skb); 1339 for (i = 0; i < ROLLOVER_HLEN; i++) 1340 if (po->rollover->history[i] == rxhash) 1341 count++; 1342 1343 po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash; 1344 return count > (ROLLOVER_HLEN >> 1); 1345 } 1346 1347 static unsigned int fanout_demux_hash(struct packet_fanout *f, 1348 struct sk_buff *skb, 1349 unsigned int num) 1350 { 1351 return reciprocal_scale(__skb_get_hash_symmetric(skb), num); 1352 } 1353 1354 static unsigned int fanout_demux_lb(struct packet_fanout *f, 1355 struct sk_buff *skb, 1356 unsigned int num) 1357 { 1358 unsigned int val = atomic_inc_return(&f->rr_cur); 1359 1360 return val % num; 1361 } 1362 1363 static unsigned int fanout_demux_cpu(struct packet_fanout *f, 1364 struct sk_buff *skb, 1365 unsigned int num) 1366 { 1367 return smp_processor_id() % num; 1368 } 1369 1370 static unsigned int fanout_demux_rnd(struct packet_fanout *f, 1371 struct sk_buff *skb, 1372 unsigned int num) 1373 { 1374 return prandom_u32_max(num); 1375 } 1376 1377 static unsigned int fanout_demux_rollover(struct packet_fanout *f, 1378 struct sk_buff *skb, 1379 unsigned int idx, bool try_self, 1380 unsigned int num) 1381 { 1382 struct packet_sock *po, *po_next, *po_skip = NULL; 1383 unsigned int i, j, room = ROOM_NONE; 1384 1385 po = pkt_sk(f->arr[idx]); 1386 1387 if (try_self) { 1388 room = packet_rcv_has_room(po, skb); 1389 if (room == ROOM_NORMAL || 1390 (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) 1391 return idx; 1392 po_skip = po; 1393 } 1394 1395 i = j = min_t(int, po->rollover->sock, num - 1); 1396 do { 1397 po_next = pkt_sk(f->arr[i]); 1398 if (po_next != po_skip && !po_next->pressure && 1399 packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { 1400 if (i != j) 1401 po->rollover->sock = i; 1402 atomic_long_inc(&po->rollover->num); 1403 if (room == ROOM_LOW) 1404 atomic_long_inc(&po->rollover->num_huge); 1405 return i; 1406 } 1407 1408 if (++i == num) 1409 i = 0; 1410 } while (i != j); 1411 1412 atomic_long_inc(&po->rollover->num_failed); 1413 return idx; 1414 } 1415 1416 static unsigned int fanout_demux_qm(struct packet_fanout *f, 1417 struct sk_buff *skb, 1418 unsigned int num) 1419 { 1420 return skb_get_queue_mapping(skb) % num; 1421 } 1422 1423 static unsigned int fanout_demux_bpf(struct packet_fanout *f, 1424 struct sk_buff *skb, 1425 unsigned int num) 1426 { 1427 struct bpf_prog *prog; 1428 unsigned int ret = 0; 1429 1430 rcu_read_lock(); 1431 prog = rcu_dereference(f->bpf_prog); 1432 if (prog) 1433 ret = bpf_prog_run_clear_cb(prog, skb) % num; 1434 rcu_read_unlock(); 1435 1436 return ret; 1437 } 1438 1439 static bool fanout_has_flag(struct packet_fanout *f, u16 flag) 1440 { 1441 return f->flags & (flag >> 8); 1442 } 1443 1444 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 1445 struct packet_type *pt, struct net_device *orig_dev) 1446 { 1447 struct packet_fanout *f = pt->af_packet_priv; 1448 unsigned int num = READ_ONCE(f->num_members); 1449 struct net *net = read_pnet(&f->net); 1450 struct packet_sock *po; 1451 unsigned int idx; 1452 1453 if (!net_eq(dev_net(dev), net) || !num) { 1454 kfree_skb(skb); 1455 return 0; 1456 } 1457 1458 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { 1459 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); 1460 if (!skb) 1461 return 0; 1462 } 1463 switch (f->type) { 1464 case PACKET_FANOUT_HASH: 1465 default: 1466 idx = fanout_demux_hash(f, skb, num); 1467 break; 1468 case PACKET_FANOUT_LB: 1469 idx = fanout_demux_lb(f, skb, num); 1470 break; 1471 case PACKET_FANOUT_CPU: 1472 idx = fanout_demux_cpu(f, skb, num); 1473 break; 1474 case PACKET_FANOUT_RND: 1475 idx = fanout_demux_rnd(f, skb, num); 1476 break; 1477 case PACKET_FANOUT_QM: 1478 idx = fanout_demux_qm(f, skb, num); 1479 break; 1480 case PACKET_FANOUT_ROLLOVER: 1481 idx = fanout_demux_rollover(f, skb, 0, false, num); 1482 break; 1483 case PACKET_FANOUT_CBPF: 1484 case PACKET_FANOUT_EBPF: 1485 idx = fanout_demux_bpf(f, skb, num); 1486 break; 1487 } 1488 1489 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) 1490 idx = fanout_demux_rollover(f, skb, idx, true, num); 1491 1492 po = pkt_sk(f->arr[idx]); 1493 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); 1494 } 1495 1496 DEFINE_MUTEX(fanout_mutex); 1497 EXPORT_SYMBOL_GPL(fanout_mutex); 1498 static LIST_HEAD(fanout_list); 1499 1500 static void __fanout_link(struct sock *sk, struct packet_sock *po) 1501 { 1502 struct packet_fanout *f = po->fanout; 1503 1504 spin_lock(&f->lock); 1505 f->arr[f->num_members] = sk; 1506 smp_wmb(); 1507 f->num_members++; 1508 if (f->num_members == 1) 1509 dev_add_pack(&f->prot_hook); 1510 spin_unlock(&f->lock); 1511 } 1512 1513 static void __fanout_unlink(struct sock *sk, struct packet_sock *po) 1514 { 1515 struct packet_fanout *f = po->fanout; 1516 int i; 1517 1518 spin_lock(&f->lock); 1519 for (i = 0; i < f->num_members; i++) { 1520 if (f->arr[i] == sk) 1521 break; 1522 } 1523 BUG_ON(i >= f->num_members); 1524 f->arr[i] = f->arr[f->num_members - 1]; 1525 f->num_members--; 1526 if (f->num_members == 0) 1527 __dev_remove_pack(&f->prot_hook); 1528 spin_unlock(&f->lock); 1529 } 1530 1531 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) 1532 { 1533 if (sk->sk_family != PF_PACKET) 1534 return false; 1535 1536 return ptype->af_packet_priv == pkt_sk(sk)->fanout; 1537 } 1538 1539 static void fanout_init_data(struct packet_fanout *f) 1540 { 1541 switch (f->type) { 1542 case PACKET_FANOUT_LB: 1543 atomic_set(&f->rr_cur, 0); 1544 break; 1545 case PACKET_FANOUT_CBPF: 1546 case PACKET_FANOUT_EBPF: 1547 RCU_INIT_POINTER(f->bpf_prog, NULL); 1548 break; 1549 } 1550 } 1551 1552 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) 1553 { 1554 struct bpf_prog *old; 1555 1556 spin_lock(&f->lock); 1557 old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); 1558 rcu_assign_pointer(f->bpf_prog, new); 1559 spin_unlock(&f->lock); 1560 1561 if (old) { 1562 synchronize_net(); 1563 bpf_prog_destroy(old); 1564 } 1565 } 1566 1567 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data, 1568 unsigned int len) 1569 { 1570 struct bpf_prog *new; 1571 struct sock_fprog fprog; 1572 int ret; 1573 1574 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1575 return -EPERM; 1576 if (len != sizeof(fprog)) 1577 return -EINVAL; 1578 if (copy_from_user(&fprog, data, len)) 1579 return -EFAULT; 1580 1581 ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); 1582 if (ret) 1583 return ret; 1584 1585 __fanout_set_data_bpf(po->fanout, new); 1586 return 0; 1587 } 1588 1589 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data, 1590 unsigned int len) 1591 { 1592 struct bpf_prog *new; 1593 u32 fd; 1594 1595 if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) 1596 return -EPERM; 1597 if (len != sizeof(fd)) 1598 return -EINVAL; 1599 if (copy_from_user(&fd, data, len)) 1600 return -EFAULT; 1601 1602 new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); 1603 if (IS_ERR(new)) 1604 return PTR_ERR(new); 1605 1606 __fanout_set_data_bpf(po->fanout, new); 1607 return 0; 1608 } 1609 1610 static int fanout_set_data(struct packet_sock *po, char __user *data, 1611 unsigned int len) 1612 { 1613 switch (po->fanout->type) { 1614 case PACKET_FANOUT_CBPF: 1615 return fanout_set_data_cbpf(po, data, len); 1616 case PACKET_FANOUT_EBPF: 1617 return fanout_set_data_ebpf(po, data, len); 1618 default: 1619 return -EINVAL; 1620 }; 1621 } 1622 1623 static void fanout_release_data(struct packet_fanout *f) 1624 { 1625 switch (f->type) { 1626 case PACKET_FANOUT_CBPF: 1627 case PACKET_FANOUT_EBPF: 1628 __fanout_set_data_bpf(f, NULL); 1629 }; 1630 } 1631 1632 static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 1633 { 1634 struct packet_rollover *rollover = NULL; 1635 struct packet_sock *po = pkt_sk(sk); 1636 struct packet_fanout *f, *match; 1637 u8 type = type_flags & 0xff; 1638 u8 flags = type_flags >> 8; 1639 int err; 1640 1641 switch (type) { 1642 case PACKET_FANOUT_ROLLOVER: 1643 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) 1644 return -EINVAL; 1645 case PACKET_FANOUT_HASH: 1646 case PACKET_FANOUT_LB: 1647 case PACKET_FANOUT_CPU: 1648 case PACKET_FANOUT_RND: 1649 case PACKET_FANOUT_QM: 1650 case PACKET_FANOUT_CBPF: 1651 case PACKET_FANOUT_EBPF: 1652 break; 1653 default: 1654 return -EINVAL; 1655 } 1656 1657 mutex_lock(&fanout_mutex); 1658 1659 err = -EINVAL; 1660 if (!po->running) 1661 goto out; 1662 1663 err = -EALREADY; 1664 if (po->fanout) 1665 goto out; 1666 1667 if (type == PACKET_FANOUT_ROLLOVER || 1668 (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { 1669 err = -ENOMEM; 1670 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); 1671 if (!rollover) 1672 goto out; 1673 atomic_long_set(&rollover->num, 0); 1674 atomic_long_set(&rollover->num_huge, 0); 1675 atomic_long_set(&rollover->num_failed, 0); 1676 po->rollover = rollover; 1677 } 1678 1679 match = NULL; 1680 list_for_each_entry(f, &fanout_list, list) { 1681 if (f->id == id && 1682 read_pnet(&f->net) == sock_net(sk)) { 1683 match = f; 1684 break; 1685 } 1686 } 1687 err = -EINVAL; 1688 if (match && match->flags != flags) 1689 goto out; 1690 if (!match) { 1691 err = -ENOMEM; 1692 match = kzalloc(sizeof(*match), GFP_KERNEL); 1693 if (!match) 1694 goto out; 1695 write_pnet(&match->net, sock_net(sk)); 1696 match->id = id; 1697 match->type = type; 1698 match->flags = flags; 1699 INIT_LIST_HEAD(&match->list); 1700 spin_lock_init(&match->lock); 1701 atomic_set(&match->sk_ref, 0); 1702 fanout_init_data(match); 1703 match->prot_hook.type = po->prot_hook.type; 1704 match->prot_hook.dev = po->prot_hook.dev; 1705 match->prot_hook.func = packet_rcv_fanout; 1706 match->prot_hook.af_packet_priv = match; 1707 match->prot_hook.id_match = match_fanout_group; 1708 list_add(&match->list, &fanout_list); 1709 } 1710 err = -EINVAL; 1711 if (match->type == type && 1712 match->prot_hook.type == po->prot_hook.type && 1713 match->prot_hook.dev == po->prot_hook.dev) { 1714 err = -ENOSPC; 1715 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) { 1716 __dev_remove_pack(&po->prot_hook); 1717 po->fanout = match; 1718 atomic_inc(&match->sk_ref); 1719 __fanout_link(sk, po); 1720 err = 0; 1721 } 1722 } 1723 out: 1724 if (err && rollover) { 1725 kfree(rollover); 1726 po->rollover = NULL; 1727 } 1728 mutex_unlock(&fanout_mutex); 1729 return err; 1730 } 1731 1732 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes 1733 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. 1734 * It is the responsibility of the caller to call fanout_release_data() and 1735 * free the returned packet_fanout (after synchronize_net()) 1736 */ 1737 static struct packet_fanout *fanout_release(struct sock *sk) 1738 { 1739 struct packet_sock *po = pkt_sk(sk); 1740 struct packet_fanout *f; 1741 1742 mutex_lock(&fanout_mutex); 1743 f = po->fanout; 1744 if (f) { 1745 po->fanout = NULL; 1746 1747 if (atomic_dec_and_test(&f->sk_ref)) 1748 list_del(&f->list); 1749 else 1750 f = NULL; 1751 1752 if (po->rollover) 1753 kfree_rcu(po->rollover, rcu); 1754 } 1755 mutex_unlock(&fanout_mutex); 1756 1757 return f; 1758 } 1759 1760 static bool packet_extra_vlan_len_allowed(const struct net_device *dev, 1761 struct sk_buff *skb) 1762 { 1763 /* Earlier code assumed this would be a VLAN pkt, double-check 1764 * this now that we have the actual packet in hand. We can only 1765 * do this check on Ethernet devices. 1766 */ 1767 if (unlikely(dev->type != ARPHRD_ETHER)) 1768 return false; 1769 1770 skb_reset_mac_header(skb); 1771 return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); 1772 } 1773 1774 static const struct proto_ops packet_ops; 1775 1776 static const struct proto_ops packet_ops_spkt; 1777 1778 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, 1779 struct packet_type *pt, struct net_device *orig_dev) 1780 { 1781 struct sock *sk; 1782 struct sockaddr_pkt *spkt; 1783 1784 /* 1785 * When we registered the protocol we saved the socket in the data 1786 * field for just this event. 1787 */ 1788 1789 sk = pt->af_packet_priv; 1790 1791 /* 1792 * Yank back the headers [hope the device set this 1793 * right or kerboom...] 1794 * 1795 * Incoming packets have ll header pulled, 1796 * push it back. 1797 * 1798 * For outgoing ones skb->data == skb_mac_header(skb) 1799 * so that this procedure is noop. 1800 */ 1801 1802 if (skb->pkt_type == PACKET_LOOPBACK) 1803 goto out; 1804 1805 if (!net_eq(dev_net(dev), sock_net(sk))) 1806 goto out; 1807 1808 skb = skb_share_check(skb, GFP_ATOMIC); 1809 if (skb == NULL) 1810 goto oom; 1811 1812 /* drop any routing info */ 1813 skb_dst_drop(skb); 1814 1815 /* drop conntrack reference */ 1816 nf_reset(skb); 1817 1818 spkt = &PACKET_SKB_CB(skb)->sa.pkt; 1819 1820 skb_push(skb, skb->data - skb_mac_header(skb)); 1821 1822 /* 1823 * The SOCK_PACKET socket receives _all_ frames. 1824 */ 1825 1826 spkt->spkt_family = dev->type; 1827 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); 1828 spkt->spkt_protocol = skb->protocol; 1829 1830 /* 1831 * Charge the memory to the socket. This is done specifically 1832 * to prevent sockets using all the memory up. 1833 */ 1834 1835 if (sock_queue_rcv_skb(sk, skb) == 0) 1836 return 0; 1837 1838 out: 1839 kfree_skb(skb); 1840 oom: 1841 return 0; 1842 } 1843 1844 1845 /* 1846 * Output a raw packet to a device layer. This bypasses all the other 1847 * protocol layers and you must therefore supply it with a complete frame 1848 */ 1849 1850 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, 1851 size_t len) 1852 { 1853 struct sock *sk = sock->sk; 1854 DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); 1855 struct sk_buff *skb = NULL; 1856 struct net_device *dev; 1857 struct sockcm_cookie sockc; 1858 __be16 proto = 0; 1859 int err; 1860 int extra_len = 0; 1861 1862 /* 1863 * Get and verify the address. 1864 */ 1865 1866 if (saddr) { 1867 if (msg->msg_namelen < sizeof(struct sockaddr)) 1868 return -EINVAL; 1869 if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) 1870 proto = saddr->spkt_protocol; 1871 } else 1872 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ 1873 1874 /* 1875 * Find the device first to size check it 1876 */ 1877 1878 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; 1879 retry: 1880 rcu_read_lock(); 1881 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); 1882 err = -ENODEV; 1883 if (dev == NULL) 1884 goto out_unlock; 1885 1886 err = -ENETDOWN; 1887 if (!(dev->flags & IFF_UP)) 1888 goto out_unlock; 1889 1890 /* 1891 * You may not queue a frame bigger than the mtu. This is the lowest level 1892 * raw protocol and you must do your own fragmentation at this level. 1893 */ 1894 1895 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 1896 if (!netif_supports_nofcs(dev)) { 1897 err = -EPROTONOSUPPORT; 1898 goto out_unlock; 1899 } 1900 extra_len = 4; /* We're doing our own CRC */ 1901 } 1902 1903 err = -EMSGSIZE; 1904 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) 1905 goto out_unlock; 1906 1907 if (!skb) { 1908 size_t reserved = LL_RESERVED_SPACE(dev); 1909 int tlen = dev->needed_tailroom; 1910 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; 1911 1912 rcu_read_unlock(); 1913 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); 1914 if (skb == NULL) 1915 return -ENOBUFS; 1916 /* FIXME: Save some space for broken drivers that write a hard 1917 * header at transmission time by themselves. PPP is the notable 1918 * one here. This should really be fixed at the driver level. 1919 */ 1920 skb_reserve(skb, reserved); 1921 skb_reset_network_header(skb); 1922 1923 /* Try to align data part correctly */ 1924 if (hhlen) { 1925 skb->data -= hhlen; 1926 skb->tail -= hhlen; 1927 if (len < hhlen) 1928 skb_reset_network_header(skb); 1929 } 1930 err = memcpy_from_msg(skb_put(skb, len), msg, len); 1931 if (err) 1932 goto out_free; 1933 goto retry; 1934 } 1935 1936 if (!dev_validate_header(dev, skb->data, len)) { 1937 err = -EINVAL; 1938 goto out_unlock; 1939 } 1940 if (len > (dev->mtu + dev->hard_header_len + extra_len) && 1941 !packet_extra_vlan_len_allowed(dev, skb)) { 1942 err = -EMSGSIZE; 1943 goto out_unlock; 1944 } 1945 1946 sockc.tsflags = sk->sk_tsflags; 1947 if (msg->msg_controllen) { 1948 err = sock_cmsg_send(sk, msg, &sockc); 1949 if (unlikely(err)) 1950 goto out_unlock; 1951 } 1952 1953 skb->protocol = proto; 1954 skb->dev = dev; 1955 skb->priority = sk->sk_priority; 1956 skb->mark = sk->sk_mark; 1957 1958 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags); 1959 1960 if (unlikely(extra_len == 4)) 1961 skb->no_fcs = 1; 1962 1963 skb_probe_transport_header(skb, 0); 1964 1965 dev_queue_xmit(skb); 1966 rcu_read_unlock(); 1967 return len; 1968 1969 out_unlock: 1970 rcu_read_unlock(); 1971 out_free: 1972 kfree_skb(skb); 1973 return err; 1974 } 1975 1976 static unsigned int run_filter(struct sk_buff *skb, 1977 const struct sock *sk, 1978 unsigned int res) 1979 { 1980 struct sk_filter *filter; 1981 1982 rcu_read_lock(); 1983 filter = rcu_dereference(sk->sk_filter); 1984 if (filter != NULL) 1985 res = bpf_prog_run_clear_cb(filter->prog, skb); 1986 rcu_read_unlock(); 1987 1988 return res; 1989 } 1990 1991 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, 1992 size_t *len) 1993 { 1994 struct virtio_net_hdr vnet_hdr; 1995 1996 if (*len < sizeof(vnet_hdr)) 1997 return -EINVAL; 1998 *len -= sizeof(vnet_hdr); 1999 2000 if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true)) 2001 return -EINVAL; 2002 2003 return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr)); 2004 } 2005 2006 /* 2007 * This function makes lazy skb cloning in hope that most of packets 2008 * are discarded by BPF. 2009 * 2010 * Note tricky part: we DO mangle shared skb! skb->data, skb->len 2011 * and skb->cb are mangled. It works because (and until) packets 2012 * falling here are owned by current CPU. Output packets are cloned 2013 * by dev_queue_xmit_nit(), input packets are processed by net_bh 2014 * sequencially, so that if we return skb to original state on exit, 2015 * we will not harm anyone. 2016 */ 2017 2018 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 2019 struct packet_type *pt, struct net_device *orig_dev) 2020 { 2021 struct sock *sk; 2022 struct sockaddr_ll *sll; 2023 struct packet_sock *po; 2024 u8 *skb_head = skb->data; 2025 int skb_len = skb->len; 2026 unsigned int snaplen, res; 2027 bool is_drop_n_account = false; 2028 2029 if (skb->pkt_type == PACKET_LOOPBACK) 2030 goto drop; 2031 2032 sk = pt->af_packet_priv; 2033 po = pkt_sk(sk); 2034 2035 if (!net_eq(dev_net(dev), sock_net(sk))) 2036 goto drop; 2037 2038 skb->dev = dev; 2039 2040 if (dev->header_ops) { 2041 /* The device has an explicit notion of ll header, 2042 * exported to higher levels. 2043 * 2044 * Otherwise, the device hides details of its frame 2045 * structure, so that corresponding packet head is 2046 * never delivered to user. 2047 */ 2048 if (sk->sk_type != SOCK_DGRAM) 2049 skb_push(skb, skb->data - skb_mac_header(skb)); 2050 else if (skb->pkt_type == PACKET_OUTGOING) { 2051 /* Special case: outgoing packets have ll header at head */ 2052 skb_pull(skb, skb_network_offset(skb)); 2053 } 2054 } 2055 2056 snaplen = skb->len; 2057 2058 res = run_filter(skb, sk, snaplen); 2059 if (!res) 2060 goto drop_n_restore; 2061 if (snaplen > res) 2062 snaplen = res; 2063 2064 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) 2065 goto drop_n_acct; 2066 2067 if (skb_shared(skb)) { 2068 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); 2069 if (nskb == NULL) 2070 goto drop_n_acct; 2071 2072 if (skb_head != skb->data) { 2073 skb->data = skb_head; 2074 skb->len = skb_len; 2075 } 2076 consume_skb(skb); 2077 skb = nskb; 2078 } 2079 2080 sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); 2081 2082 sll = &PACKET_SKB_CB(skb)->sa.ll; 2083 sll->sll_hatype = dev->type; 2084 sll->sll_pkttype = skb->pkt_type; 2085 if (unlikely(po->origdev)) 2086 sll->sll_ifindex = orig_dev->ifindex; 2087 else 2088 sll->sll_ifindex = dev->ifindex; 2089 2090 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2091 2092 /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). 2093 * Use their space for storing the original skb length. 2094 */ 2095 PACKET_SKB_CB(skb)->sa.origlen = skb->len; 2096 2097 if (pskb_trim(skb, snaplen)) 2098 goto drop_n_acct; 2099 2100 skb_set_owner_r(skb, sk); 2101 skb->dev = NULL; 2102 skb_dst_drop(skb); 2103 2104 /* drop conntrack reference */ 2105 nf_reset(skb); 2106 2107 spin_lock(&sk->sk_receive_queue.lock); 2108 po->stats.stats1.tp_packets++; 2109 sock_skb_set_dropcount(sk, skb); 2110 __skb_queue_tail(&sk->sk_receive_queue, skb); 2111 spin_unlock(&sk->sk_receive_queue.lock); 2112 sk->sk_data_ready(sk); 2113 return 0; 2114 2115 drop_n_acct: 2116 is_drop_n_account = true; 2117 spin_lock(&sk->sk_receive_queue.lock); 2118 po->stats.stats1.tp_drops++; 2119 atomic_inc(&sk->sk_drops); 2120 spin_unlock(&sk->sk_receive_queue.lock); 2121 2122 drop_n_restore: 2123 if (skb_head != skb->data && skb_shared(skb)) { 2124 skb->data = skb_head; 2125 skb->len = skb_len; 2126 } 2127 drop: 2128 if (!is_drop_n_account) 2129 consume_skb(skb); 2130 else 2131 kfree_skb(skb); 2132 return 0; 2133 } 2134 2135 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 2136 struct packet_type *pt, struct net_device *orig_dev) 2137 { 2138 struct sock *sk; 2139 struct packet_sock *po; 2140 struct sockaddr_ll *sll; 2141 union tpacket_uhdr h; 2142 u8 *skb_head = skb->data; 2143 int skb_len = skb->len; 2144 unsigned int snaplen, res; 2145 unsigned long status = TP_STATUS_USER; 2146 unsigned short macoff, netoff, hdrlen; 2147 struct sk_buff *copy_skb = NULL; 2148 struct timespec ts; 2149 __u32 ts_status; 2150 bool is_drop_n_account = false; 2151 2152 /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. 2153 * We may add members to them until current aligned size without forcing 2154 * userspace to call getsockopt(..., PACKET_HDRLEN, ...). 2155 */ 2156 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); 2157 BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); 2158 2159 if (skb->pkt_type == PACKET_LOOPBACK) 2160 goto drop; 2161 2162 sk = pt->af_packet_priv; 2163 po = pkt_sk(sk); 2164 2165 if (!net_eq(dev_net(dev), sock_net(sk))) 2166 goto drop; 2167 2168 if (dev->header_ops) { 2169 if (sk->sk_type != SOCK_DGRAM) 2170 skb_push(skb, skb->data - skb_mac_header(skb)); 2171 else if (skb->pkt_type == PACKET_OUTGOING) { 2172 /* Special case: outgoing packets have ll header at head */ 2173 skb_pull(skb, skb_network_offset(skb)); 2174 } 2175 } 2176 2177 snaplen = skb->len; 2178 2179 res = run_filter(skb, sk, snaplen); 2180 if (!res) 2181 goto drop_n_restore; 2182 2183 if (skb->ip_summed == CHECKSUM_PARTIAL) 2184 status |= TP_STATUS_CSUMNOTREADY; 2185 else if (skb->pkt_type != PACKET_OUTGOING && 2186 (skb->ip_summed == CHECKSUM_COMPLETE || 2187 skb_csum_unnecessary(skb))) 2188 status |= TP_STATUS_CSUM_VALID; 2189 2190 if (snaplen > res) 2191 snaplen = res; 2192 2193 if (sk->sk_type == SOCK_DGRAM) { 2194 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + 2195 po->tp_reserve; 2196 } else { 2197 unsigned int maclen = skb_network_offset(skb); 2198 netoff = TPACKET_ALIGN(po->tp_hdrlen + 2199 (maclen < 16 ? 16 : maclen)) + 2200 po->tp_reserve; 2201 if (po->has_vnet_hdr) 2202 netoff += sizeof(struct virtio_net_hdr); 2203 macoff = netoff - maclen; 2204 } 2205 if (po->tp_version <= TPACKET_V2) { 2206 if (macoff + snaplen > po->rx_ring.frame_size) { 2207 if (po->copy_thresh && 2208 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { 2209 if (skb_shared(skb)) { 2210 copy_skb = skb_clone(skb, GFP_ATOMIC); 2211 } else { 2212 copy_skb = skb_get(skb); 2213 skb_head = skb->data; 2214 } 2215 if (copy_skb) 2216 skb_set_owner_r(copy_skb, sk); 2217 } 2218 snaplen = po->rx_ring.frame_size - macoff; 2219 if ((int)snaplen < 0) 2220 snaplen = 0; 2221 } 2222 } else if (unlikely(macoff + snaplen > 2223 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { 2224 u32 nval; 2225 2226 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; 2227 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", 2228 snaplen, nval, macoff); 2229 snaplen = nval; 2230 if (unlikely((int)snaplen < 0)) { 2231 snaplen = 0; 2232 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; 2233 } 2234 } 2235 spin_lock(&sk->sk_receive_queue.lock); 2236 h.raw = packet_current_rx_frame(po, skb, 2237 TP_STATUS_KERNEL, (macoff+snaplen)); 2238 if (!h.raw) 2239 goto drop_n_account; 2240 if (po->tp_version <= TPACKET_V2) { 2241 packet_increment_rx_head(po, &po->rx_ring); 2242 /* 2243 * LOSING will be reported till you read the stats, 2244 * because it's COR - Clear On Read. 2245 * Anyways, moving it for V1/V2 only as V3 doesn't need this 2246 * at packet level. 2247 */ 2248 if (po->stats.stats1.tp_drops) 2249 status |= TP_STATUS_LOSING; 2250 } 2251 po->stats.stats1.tp_packets++; 2252 if (copy_skb) { 2253 status |= TP_STATUS_COPY; 2254 __skb_queue_tail(&sk->sk_receive_queue, copy_skb); 2255 } 2256 spin_unlock(&sk->sk_receive_queue.lock); 2257 2258 if (po->has_vnet_hdr) { 2259 if (virtio_net_hdr_from_skb(skb, h.raw + macoff - 2260 sizeof(struct virtio_net_hdr), 2261 vio_le(), true)) { 2262 spin_lock(&sk->sk_receive_queue.lock); 2263 goto drop_n_account; 2264 } 2265 } 2266 2267 skb_copy_bits(skb, 0, h.raw + macoff, snaplen); 2268 2269 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp))) 2270 getnstimeofday(&ts); 2271 2272 status |= ts_status; 2273 2274 switch (po->tp_version) { 2275 case TPACKET_V1: 2276 h.h1->tp_len = skb->len; 2277 h.h1->tp_snaplen = snaplen; 2278 h.h1->tp_mac = macoff; 2279 h.h1->tp_net = netoff; 2280 h.h1->tp_sec = ts.tv_sec; 2281 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; 2282 hdrlen = sizeof(*h.h1); 2283 break; 2284 case TPACKET_V2: 2285 h.h2->tp_len = skb->len; 2286 h.h2->tp_snaplen = snaplen; 2287 h.h2->tp_mac = macoff; 2288 h.h2->tp_net = netoff; 2289 h.h2->tp_sec = ts.tv_sec; 2290 h.h2->tp_nsec = ts.tv_nsec; 2291 if (skb_vlan_tag_present(skb)) { 2292 h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); 2293 h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); 2294 status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 2295 } else { 2296 h.h2->tp_vlan_tci = 0; 2297 h.h2->tp_vlan_tpid = 0; 2298 } 2299 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); 2300 hdrlen = sizeof(*h.h2); 2301 break; 2302 case TPACKET_V3: 2303 /* tp_nxt_offset,vlan are already populated above. 2304 * So DONT clear those fields here 2305 */ 2306 h.h3->tp_status |= status; 2307 h.h3->tp_len = skb->len; 2308 h.h3->tp_snaplen = snaplen; 2309 h.h3->tp_mac = macoff; 2310 h.h3->tp_net = netoff; 2311 h.h3->tp_sec = ts.tv_sec; 2312 h.h3->tp_nsec = ts.tv_nsec; 2313 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); 2314 hdrlen = sizeof(*h.h3); 2315 break; 2316 default: 2317 BUG(); 2318 } 2319 2320 sll = h.raw + TPACKET_ALIGN(hdrlen); 2321 sll->sll_halen = dev_parse_header(skb, sll->sll_addr); 2322 sll->sll_family = AF_PACKET; 2323 sll->sll_hatype = dev->type; 2324 sll->sll_protocol = skb->protocol; 2325 sll->sll_pkttype = skb->pkt_type; 2326 if (unlikely(po->origdev)) 2327 sll->sll_ifindex = orig_dev->ifindex; 2328 else 2329 sll->sll_ifindex = dev->ifindex; 2330 2331 smp_mb(); 2332 2333 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 2334 if (po->tp_version <= TPACKET_V2) { 2335 u8 *start, *end; 2336 2337 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + 2338 macoff + snaplen); 2339 2340 for (start = h.raw; start < end; start += PAGE_SIZE) 2341 flush_dcache_page(pgv_to_page(start)); 2342 } 2343 smp_wmb(); 2344 #endif 2345 2346 if (po->tp_version <= TPACKET_V2) { 2347 __packet_set_status(po, h.raw, status); 2348 sk->sk_data_ready(sk); 2349 } else { 2350 prb_clear_blk_fill_status(&po->rx_ring); 2351 } 2352 2353 drop_n_restore: 2354 if (skb_head != skb->data && skb_shared(skb)) { 2355 skb->data = skb_head; 2356 skb->len = skb_len; 2357 } 2358 drop: 2359 if (!is_drop_n_account) 2360 consume_skb(skb); 2361 else 2362 kfree_skb(skb); 2363 return 0; 2364 2365 drop_n_account: 2366 is_drop_n_account = true; 2367 po->stats.stats1.tp_drops++; 2368 spin_unlock(&sk->sk_receive_queue.lock); 2369 2370 sk->sk_data_ready(sk); 2371 kfree_skb(copy_skb); 2372 goto drop_n_restore; 2373 } 2374 2375 static void tpacket_destruct_skb(struct sk_buff *skb) 2376 { 2377 struct packet_sock *po = pkt_sk(skb->sk); 2378 2379 if (likely(po->tx_ring.pg_vec)) { 2380 void *ph; 2381 __u32 ts; 2382 2383 ph = skb_shinfo(skb)->destructor_arg; 2384 packet_dec_pending(&po->tx_ring); 2385 2386 ts = __packet_set_timestamp(po, ph, skb); 2387 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); 2388 } 2389 2390 sock_wfree(skb); 2391 } 2392 2393 static void tpacket_set_protocol(const struct net_device *dev, 2394 struct sk_buff *skb) 2395 { 2396 if (dev->type == ARPHRD_ETHER) { 2397 skb_reset_mac_header(skb); 2398 skb->protocol = eth_hdr(skb)->h_proto; 2399 } 2400 } 2401 2402 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) 2403 { 2404 if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 2405 (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2406 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > 2407 __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) 2408 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), 2409 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + 2410 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); 2411 2412 if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) 2413 return -EINVAL; 2414 2415 return 0; 2416 } 2417 2418 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, 2419 struct virtio_net_hdr *vnet_hdr) 2420 { 2421 if (*len < sizeof(*vnet_hdr)) 2422 return -EINVAL; 2423 *len -= sizeof(*vnet_hdr); 2424 2425 if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) 2426 return -EFAULT; 2427 2428 return __packet_snd_vnet_parse(vnet_hdr, *len); 2429 } 2430 2431 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 2432 void *frame, struct net_device *dev, void *data, int tp_len, 2433 __be16 proto, unsigned char *addr, int hlen, int copylen, 2434 const struct sockcm_cookie *sockc) 2435 { 2436 union tpacket_uhdr ph; 2437 int to_write, offset, len, nr_frags, len_max; 2438 struct socket *sock = po->sk.sk_socket; 2439 struct page *page; 2440 int err; 2441 2442 ph.raw = frame; 2443 2444 skb->protocol = proto; 2445 skb->dev = dev; 2446 skb->priority = po->sk.sk_priority; 2447 skb->mark = po->sk.sk_mark; 2448 sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags); 2449 skb_shinfo(skb)->destructor_arg = ph.raw; 2450 2451 skb_reserve(skb, hlen); 2452 skb_reset_network_header(skb); 2453 2454 to_write = tp_len; 2455 2456 if (sock->type == SOCK_DGRAM) { 2457 err = dev_hard_header(skb, dev, ntohs(proto), addr, 2458 NULL, tp_len); 2459 if (unlikely(err < 0)) 2460 return -EINVAL; 2461 } else if (copylen) { 2462 int hdrlen = min_t(int, copylen, tp_len); 2463 2464 skb_push(skb, dev->hard_header_len); 2465 skb_put(skb, copylen - dev->hard_header_len); 2466 err = skb_store_bits(skb, 0, data, hdrlen); 2467 if (unlikely(err)) 2468 return err; 2469 if (!dev_validate_header(dev, skb->data, hdrlen)) 2470 return -EINVAL; 2471 if (!skb->protocol) 2472 tpacket_set_protocol(dev, skb); 2473 2474 data += hdrlen; 2475 to_write -= hdrlen; 2476 } 2477 2478 offset = offset_in_page(data); 2479 len_max = PAGE_SIZE - offset; 2480 len = ((to_write > len_max) ? len_max : to_write); 2481 2482 skb->data_len = to_write; 2483 skb->len += to_write; 2484 skb->truesize += to_write; 2485 atomic_add(to_write, &po->sk.sk_wmem_alloc); 2486 2487 while (likely(to_write)) { 2488 nr_frags = skb_shinfo(skb)->nr_frags; 2489 2490 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { 2491 pr_err("Packet exceed the number of skb frags(%lu)\n", 2492 MAX_SKB_FRAGS); 2493 return -EFAULT; 2494 } 2495 2496 page = pgv_to_page(data); 2497 data += len; 2498 flush_dcache_page(page); 2499 get_page(page); 2500 skb_fill_page_desc(skb, nr_frags, page, offset, len); 2501 to_write -= len; 2502 offset = 0; 2503 len_max = PAGE_SIZE; 2504 len = ((to_write > len_max) ? len_max : to_write); 2505 } 2506 2507 skb_probe_transport_header(skb, 0); 2508 2509 return tp_len; 2510 } 2511 2512 static int tpacket_parse_header(struct packet_sock *po, void *frame, 2513 int size_max, void **data) 2514 { 2515 union tpacket_uhdr ph; 2516 int tp_len, off; 2517 2518 ph.raw = frame; 2519 2520 switch (po->tp_version) { 2521 case TPACKET_V3: 2522 if (ph.h3->tp_next_offset != 0) { 2523 pr_warn_once("variable sized slot not supported"); 2524 return -EINVAL; 2525 } 2526 tp_len = ph.h3->tp_len; 2527 break; 2528 case TPACKET_V2: 2529 tp_len = ph.h2->tp_len; 2530 break; 2531 default: 2532 tp_len = ph.h1->tp_len; 2533 break; 2534 } 2535 if (unlikely(tp_len > size_max)) { 2536 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); 2537 return -EMSGSIZE; 2538 } 2539 2540 if (unlikely(po->tp_tx_has_off)) { 2541 int off_min, off_max; 2542 2543 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2544 off_max = po->tx_ring.frame_size - tp_len; 2545 if (po->sk.sk_type == SOCK_DGRAM) { 2546 switch (po->tp_version) { 2547 case TPACKET_V3: 2548 off = ph.h3->tp_net; 2549 break; 2550 case TPACKET_V2: 2551 off = ph.h2->tp_net; 2552 break; 2553 default: 2554 off = ph.h1->tp_net; 2555 break; 2556 } 2557 } else { 2558 switch (po->tp_version) { 2559 case TPACKET_V3: 2560 off = ph.h3->tp_mac; 2561 break; 2562 case TPACKET_V2: 2563 off = ph.h2->tp_mac; 2564 break; 2565 default: 2566 off = ph.h1->tp_mac; 2567 break; 2568 } 2569 } 2570 if (unlikely((off < off_min) || (off_max < off))) 2571 return -EINVAL; 2572 } else { 2573 off = po->tp_hdrlen - sizeof(struct sockaddr_ll); 2574 } 2575 2576 *data = frame + off; 2577 return tp_len; 2578 } 2579 2580 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 2581 { 2582 struct sk_buff *skb; 2583 struct net_device *dev; 2584 struct virtio_net_hdr *vnet_hdr = NULL; 2585 struct sockcm_cookie sockc; 2586 __be16 proto; 2587 int err, reserve = 0; 2588 void *ph; 2589 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2590 bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); 2591 int tp_len, size_max; 2592 unsigned char *addr; 2593 void *data; 2594 int len_sum = 0; 2595 int status = TP_STATUS_AVAILABLE; 2596 int hlen, tlen, copylen = 0; 2597 2598 mutex_lock(&po->pg_vec_lock); 2599 2600 if (likely(saddr == NULL)) { 2601 dev = packet_cached_dev_get(po); 2602 proto = po->num; 2603 addr = NULL; 2604 } else { 2605 err = -EINVAL; 2606 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2607 goto out; 2608 if (msg->msg_namelen < (saddr->sll_halen 2609 + offsetof(struct sockaddr_ll, 2610 sll_addr))) 2611 goto out; 2612 proto = saddr->sll_protocol; 2613 addr = saddr->sll_addr; 2614 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); 2615 } 2616 2617 sockc.tsflags = po->sk.sk_tsflags; 2618 if (msg->msg_controllen) { 2619 err = sock_cmsg_send(&po->sk, msg, &sockc); 2620 if (unlikely(err)) 2621 goto out; 2622 } 2623 2624 err = -ENXIO; 2625 if (unlikely(dev == NULL)) 2626 goto out; 2627 err = -ENETDOWN; 2628 if (unlikely(!(dev->flags & IFF_UP))) 2629 goto out_put; 2630 2631 if (po->sk.sk_socket->type == SOCK_RAW) 2632 reserve = dev->hard_header_len; 2633 size_max = po->tx_ring.frame_size 2634 - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); 2635 2636 if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr) 2637 size_max = dev->mtu + reserve + VLAN_HLEN; 2638 2639 do { 2640 ph = packet_current_frame(po, &po->tx_ring, 2641 TP_STATUS_SEND_REQUEST); 2642 if (unlikely(ph == NULL)) { 2643 if (need_wait && need_resched()) 2644 schedule(); 2645 continue; 2646 } 2647 2648 skb = NULL; 2649 tp_len = tpacket_parse_header(po, ph, size_max, &data); 2650 if (tp_len < 0) 2651 goto tpacket_error; 2652 2653 status = TP_STATUS_SEND_REQUEST; 2654 hlen = LL_RESERVED_SPACE(dev); 2655 tlen = dev->needed_tailroom; 2656 if (po->has_vnet_hdr) { 2657 vnet_hdr = data; 2658 data += sizeof(*vnet_hdr); 2659 tp_len -= sizeof(*vnet_hdr); 2660 if (tp_len < 0 || 2661 __packet_snd_vnet_parse(vnet_hdr, tp_len)) { 2662 tp_len = -EINVAL; 2663 goto tpacket_error; 2664 } 2665 copylen = __virtio16_to_cpu(vio_le(), 2666 vnet_hdr->hdr_len); 2667 } 2668 copylen = max_t(int, copylen, dev->hard_header_len); 2669 skb = sock_alloc_send_skb(&po->sk, 2670 hlen + tlen + sizeof(struct sockaddr_ll) + 2671 (copylen - dev->hard_header_len), 2672 !need_wait, &err); 2673 2674 if (unlikely(skb == NULL)) { 2675 /* we assume the socket was initially writeable ... */ 2676 if (likely(len_sum > 0)) 2677 err = len_sum; 2678 goto out_status; 2679 } 2680 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, 2681 addr, hlen, copylen, &sockc); 2682 if (likely(tp_len >= 0) && 2683 tp_len > dev->mtu + reserve && 2684 !po->has_vnet_hdr && 2685 !packet_extra_vlan_len_allowed(dev, skb)) 2686 tp_len = -EMSGSIZE; 2687 2688 if (unlikely(tp_len < 0)) { 2689 tpacket_error: 2690 if (po->tp_loss) { 2691 __packet_set_status(po, ph, 2692 TP_STATUS_AVAILABLE); 2693 packet_increment_head(&po->tx_ring); 2694 kfree_skb(skb); 2695 continue; 2696 } else { 2697 status = TP_STATUS_WRONG_FORMAT; 2698 err = tp_len; 2699 goto out_status; 2700 } 2701 } 2702 2703 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr, 2704 vio_le())) { 2705 tp_len = -EINVAL; 2706 goto tpacket_error; 2707 } 2708 2709 packet_pick_tx_queue(dev, skb); 2710 2711 skb->destructor = tpacket_destruct_skb; 2712 __packet_set_status(po, ph, TP_STATUS_SENDING); 2713 packet_inc_pending(&po->tx_ring); 2714 2715 status = TP_STATUS_SEND_REQUEST; 2716 err = po->xmit(skb); 2717 if (unlikely(err > 0)) { 2718 err = net_xmit_errno(err); 2719 if (err && __packet_get_status(po, ph) == 2720 TP_STATUS_AVAILABLE) { 2721 /* skb was destructed already */ 2722 skb = NULL; 2723 goto out_status; 2724 } 2725 /* 2726 * skb was dropped but not destructed yet; 2727 * let's treat it like congestion or err < 0 2728 */ 2729 err = 0; 2730 } 2731 packet_increment_head(&po->tx_ring); 2732 len_sum += tp_len; 2733 } while (likely((ph != NULL) || 2734 /* Note: packet_read_pending() might be slow if we have 2735 * to call it as it's per_cpu variable, but in fast-path 2736 * we already short-circuit the loop with the first 2737 * condition, and luckily don't have to go that path 2738 * anyway. 2739 */ 2740 (need_wait && packet_read_pending(&po->tx_ring)))); 2741 2742 err = len_sum; 2743 goto out_put; 2744 2745 out_status: 2746 __packet_set_status(po, ph, status); 2747 kfree_skb(skb); 2748 out_put: 2749 dev_put(dev); 2750 out: 2751 mutex_unlock(&po->pg_vec_lock); 2752 return err; 2753 } 2754 2755 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, 2756 size_t reserve, size_t len, 2757 size_t linear, int noblock, 2758 int *err) 2759 { 2760 struct sk_buff *skb; 2761 2762 /* Under a page? Don't bother with paged skb. */ 2763 if (prepad + len < PAGE_SIZE || !linear) 2764 linear = len; 2765 2766 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 2767 err, 0); 2768 if (!skb) 2769 return NULL; 2770 2771 skb_reserve(skb, reserve); 2772 skb_put(skb, linear); 2773 skb->data_len = len - linear; 2774 skb->len += len - linear; 2775 2776 return skb; 2777 } 2778 2779 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 2780 { 2781 struct sock *sk = sock->sk; 2782 DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); 2783 struct sk_buff *skb; 2784 struct net_device *dev; 2785 __be16 proto; 2786 unsigned char *addr; 2787 int err, reserve = 0; 2788 struct sockcm_cookie sockc; 2789 struct virtio_net_hdr vnet_hdr = { 0 }; 2790 int offset = 0; 2791 struct packet_sock *po = pkt_sk(sk); 2792 int hlen, tlen, linear; 2793 int extra_len = 0; 2794 2795 /* 2796 * Get and verify the address. 2797 */ 2798 2799 if (likely(saddr == NULL)) { 2800 dev = packet_cached_dev_get(po); 2801 proto = po->num; 2802 addr = NULL; 2803 } else { 2804 err = -EINVAL; 2805 if (msg->msg_namelen < sizeof(struct sockaddr_ll)) 2806 goto out; 2807 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) 2808 goto out; 2809 proto = saddr->sll_protocol; 2810 addr = saddr->sll_addr; 2811 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); 2812 } 2813 2814 err = -ENXIO; 2815 if (unlikely(dev == NULL)) 2816 goto out_unlock; 2817 err = -ENETDOWN; 2818 if (unlikely(!(dev->flags & IFF_UP))) 2819 goto out_unlock; 2820 2821 sockc.tsflags = sk->sk_tsflags; 2822 sockc.mark = sk->sk_mark; 2823 if (msg->msg_controllen) { 2824 err = sock_cmsg_send(sk, msg, &sockc); 2825 if (unlikely(err)) 2826 goto out_unlock; 2827 } 2828 2829 if (sock->type == SOCK_RAW) 2830 reserve = dev->hard_header_len; 2831 if (po->has_vnet_hdr) { 2832 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr); 2833 if (err) 2834 goto out_unlock; 2835 } 2836 2837 if (unlikely(sock_flag(sk, SOCK_NOFCS))) { 2838 if (!netif_supports_nofcs(dev)) { 2839 err = -EPROTONOSUPPORT; 2840 goto out_unlock; 2841 } 2842 extra_len = 4; /* We're doing our own CRC */ 2843 } 2844 2845 err = -EMSGSIZE; 2846 if (!vnet_hdr.gso_type && 2847 (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) 2848 goto out_unlock; 2849 2850 err = -ENOBUFS; 2851 hlen = LL_RESERVED_SPACE(dev); 2852 tlen = dev->needed_tailroom; 2853 linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); 2854 linear = max(linear, min_t(int, len, dev->hard_header_len)); 2855 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, 2856 msg->msg_flags & MSG_DONTWAIT, &err); 2857 if (skb == NULL) 2858 goto out_unlock; 2859 2860 skb_set_network_header(skb, reserve); 2861 2862 err = -EINVAL; 2863 if (sock->type == SOCK_DGRAM) { 2864 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); 2865 if (unlikely(offset < 0)) 2866 goto out_free; 2867 } 2868 2869 /* Returns -EFAULT on error */ 2870 err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); 2871 if (err) 2872 goto out_free; 2873 2874 if (sock->type == SOCK_RAW && 2875 !dev_validate_header(dev, skb->data, len)) { 2876 err = -EINVAL; 2877 goto out_free; 2878 } 2879 2880 sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags); 2881 2882 if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && 2883 !packet_extra_vlan_len_allowed(dev, skb)) { 2884 err = -EMSGSIZE; 2885 goto out_free; 2886 } 2887 2888 skb->protocol = proto; 2889 skb->dev = dev; 2890 skb->priority = sk->sk_priority; 2891 skb->mark = sockc.mark; 2892 2893 packet_pick_tx_queue(dev, skb); 2894 2895 if (po->has_vnet_hdr) { 2896 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); 2897 if (err) 2898 goto out_free; 2899 len += sizeof(vnet_hdr); 2900 } 2901 2902 skb_probe_transport_header(skb, reserve); 2903 2904 if (unlikely(extra_len == 4)) 2905 skb->no_fcs = 1; 2906 2907 err = po->xmit(skb); 2908 if (err > 0 && (err = net_xmit_errno(err)) != 0) 2909 goto out_unlock; 2910 2911 dev_put(dev); 2912 2913 return len; 2914 2915 out_free: 2916 kfree_skb(skb); 2917 out_unlock: 2918 if (dev) 2919 dev_put(dev); 2920 out: 2921 return err; 2922 } 2923 2924 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 2925 { 2926 struct sock *sk = sock->sk; 2927 struct packet_sock *po = pkt_sk(sk); 2928 2929 if (po->tx_ring.pg_vec) 2930 return tpacket_snd(po, msg); 2931 else 2932 return packet_snd(sock, msg, len); 2933 } 2934 2935 /* 2936 * Close a PACKET socket. This is fairly simple. We immediately go 2937 * to 'closed' state and remove our protocol entry in the device list. 2938 */ 2939 2940 static int packet_release(struct socket *sock) 2941 { 2942 struct sock *sk = sock->sk; 2943 struct packet_sock *po; 2944 struct packet_fanout *f; 2945 struct net *net; 2946 union tpacket_req_u req_u; 2947 2948 if (!sk) 2949 return 0; 2950 2951 net = sock_net(sk); 2952 po = pkt_sk(sk); 2953 2954 mutex_lock(&net->packet.sklist_lock); 2955 sk_del_node_init_rcu(sk); 2956 mutex_unlock(&net->packet.sklist_lock); 2957 2958 preempt_disable(); 2959 sock_prot_inuse_add(net, sk->sk_prot, -1); 2960 preempt_enable(); 2961 2962 spin_lock(&po->bind_lock); 2963 unregister_prot_hook(sk, false); 2964 packet_cached_dev_reset(po); 2965 2966 if (po->prot_hook.dev) { 2967 dev_put(po->prot_hook.dev); 2968 po->prot_hook.dev = NULL; 2969 } 2970 spin_unlock(&po->bind_lock); 2971 2972 packet_flush_mclist(sk); 2973 2974 if (po->rx_ring.pg_vec) { 2975 memset(&req_u, 0, sizeof(req_u)); 2976 packet_set_ring(sk, &req_u, 1, 0); 2977 } 2978 2979 if (po->tx_ring.pg_vec) { 2980 memset(&req_u, 0, sizeof(req_u)); 2981 packet_set_ring(sk, &req_u, 1, 1); 2982 } 2983 2984 f = fanout_release(sk); 2985 2986 synchronize_net(); 2987 2988 if (f) { 2989 fanout_release_data(f); 2990 kfree(f); 2991 } 2992 /* 2993 * Now the socket is dead. No more input will appear. 2994 */ 2995 sock_orphan(sk); 2996 sock->sk = NULL; 2997 2998 /* Purge queues */ 2999 3000 skb_queue_purge(&sk->sk_receive_queue); 3001 packet_free_pending(po); 3002 sk_refcnt_debug_release(sk); 3003 3004 sock_put(sk); 3005 return 0; 3006 } 3007 3008 /* 3009 * Attach a packet hook. 3010 */ 3011 3012 static int packet_do_bind(struct sock *sk, const char *name, int ifindex, 3013 __be16 proto) 3014 { 3015 struct packet_sock *po = pkt_sk(sk); 3016 struct net_device *dev_curr; 3017 __be16 proto_curr; 3018 bool need_rehook; 3019 struct net_device *dev = NULL; 3020 int ret = 0; 3021 bool unlisted = false; 3022 3023 if (po->fanout) 3024 return -EINVAL; 3025 3026 lock_sock(sk); 3027 spin_lock(&po->bind_lock); 3028 rcu_read_lock(); 3029 3030 if (name) { 3031 dev = dev_get_by_name_rcu(sock_net(sk), name); 3032 if (!dev) { 3033 ret = -ENODEV; 3034 goto out_unlock; 3035 } 3036 } else if (ifindex) { 3037 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 3038 if (!dev) { 3039 ret = -ENODEV; 3040 goto out_unlock; 3041 } 3042 } 3043 3044 if (dev) 3045 dev_hold(dev); 3046 3047 proto_curr = po->prot_hook.type; 3048 dev_curr = po->prot_hook.dev; 3049 3050 need_rehook = proto_curr != proto || dev_curr != dev; 3051 3052 if (need_rehook) { 3053 if (po->running) { 3054 rcu_read_unlock(); 3055 __unregister_prot_hook(sk, true); 3056 rcu_read_lock(); 3057 dev_curr = po->prot_hook.dev; 3058 if (dev) 3059 unlisted = !dev_get_by_index_rcu(sock_net(sk), 3060 dev->ifindex); 3061 } 3062 3063 po->num = proto; 3064 po->prot_hook.type = proto; 3065 3066 if (unlikely(unlisted)) { 3067 dev_put(dev); 3068 po->prot_hook.dev = NULL; 3069 po->ifindex = -1; 3070 packet_cached_dev_reset(po); 3071 } else { 3072 po->prot_hook.dev = dev; 3073 po->ifindex = dev ? dev->ifindex : 0; 3074 packet_cached_dev_assign(po, dev); 3075 } 3076 } 3077 if (dev_curr) 3078 dev_put(dev_curr); 3079 3080 if (proto == 0 || !need_rehook) 3081 goto out_unlock; 3082 3083 if (!unlisted && (!dev || (dev->flags & IFF_UP))) { 3084 register_prot_hook(sk); 3085 } else { 3086 sk->sk_err = ENETDOWN; 3087 if (!sock_flag(sk, SOCK_DEAD)) 3088 sk->sk_error_report(sk); 3089 } 3090 3091 out_unlock: 3092 rcu_read_unlock(); 3093 spin_unlock(&po->bind_lock); 3094 release_sock(sk); 3095 return ret; 3096 } 3097 3098 /* 3099 * Bind a packet socket to a device 3100 */ 3101 3102 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, 3103 int addr_len) 3104 { 3105 struct sock *sk = sock->sk; 3106 char name[sizeof(uaddr->sa_data) + 1]; 3107 3108 /* 3109 * Check legality 3110 */ 3111 3112 if (addr_len != sizeof(struct sockaddr)) 3113 return -EINVAL; 3114 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be 3115 * zero-terminated. 3116 */ 3117 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data)); 3118 name[sizeof(uaddr->sa_data)] = 0; 3119 3120 return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); 3121 } 3122 3123 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3124 { 3125 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; 3126 struct sock *sk = sock->sk; 3127 3128 /* 3129 * Check legality 3130 */ 3131 3132 if (addr_len < sizeof(struct sockaddr_ll)) 3133 return -EINVAL; 3134 if (sll->sll_family != AF_PACKET) 3135 return -EINVAL; 3136 3137 return packet_do_bind(sk, NULL, sll->sll_ifindex, 3138 sll->sll_protocol ? : pkt_sk(sk)->num); 3139 } 3140 3141 static struct proto packet_proto = { 3142 .name = "PACKET", 3143 .owner = THIS_MODULE, 3144 .obj_size = sizeof(struct packet_sock), 3145 }; 3146 3147 /* 3148 * Create a packet of type SOCK_PACKET. 3149 */ 3150 3151 static int packet_create(struct net *net, struct socket *sock, int protocol, 3152 int kern) 3153 { 3154 struct sock *sk; 3155 struct packet_sock *po; 3156 __be16 proto = (__force __be16)protocol; /* weird, but documented */ 3157 int err; 3158 3159 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 3160 return -EPERM; 3161 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && 3162 sock->type != SOCK_PACKET) 3163 return -ESOCKTNOSUPPORT; 3164 3165 sock->state = SS_UNCONNECTED; 3166 3167 err = -ENOBUFS; 3168 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); 3169 if (sk == NULL) 3170 goto out; 3171 3172 sock->ops = &packet_ops; 3173 if (sock->type == SOCK_PACKET) 3174 sock->ops = &packet_ops_spkt; 3175 3176 sock_init_data(sock, sk); 3177 3178 po = pkt_sk(sk); 3179 sk->sk_family = PF_PACKET; 3180 po->num = proto; 3181 po->xmit = dev_queue_xmit; 3182 3183 err = packet_alloc_pending(po); 3184 if (err) 3185 goto out2; 3186 3187 packet_cached_dev_reset(po); 3188 3189 sk->sk_destruct = packet_sock_destruct; 3190 sk_refcnt_debug_inc(sk); 3191 3192 /* 3193 * Attach a protocol block 3194 */ 3195 3196 spin_lock_init(&po->bind_lock); 3197 mutex_init(&po->pg_vec_lock); 3198 po->rollover = NULL; 3199 po->prot_hook.func = packet_rcv; 3200 3201 if (sock->type == SOCK_PACKET) 3202 po->prot_hook.func = packet_rcv_spkt; 3203 3204 po->prot_hook.af_packet_priv = sk; 3205 3206 if (proto) { 3207 po->prot_hook.type = proto; 3208 register_prot_hook(sk); 3209 } 3210 3211 mutex_lock(&net->packet.sklist_lock); 3212 sk_add_node_rcu(sk, &net->packet.sklist); 3213 mutex_unlock(&net->packet.sklist_lock); 3214 3215 preempt_disable(); 3216 sock_prot_inuse_add(net, &packet_proto, 1); 3217 preempt_enable(); 3218 3219 return 0; 3220 out2: 3221 sk_free(sk); 3222 out: 3223 return err; 3224 } 3225 3226 /* 3227 * Pull a packet from our receive queue and hand it to the user. 3228 * If necessary we block. 3229 */ 3230 3231 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 3232 int flags) 3233 { 3234 struct sock *sk = sock->sk; 3235 struct sk_buff *skb; 3236 int copied, err; 3237 int vnet_hdr_len = 0; 3238 unsigned int origlen = 0; 3239 3240 err = -EINVAL; 3241 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) 3242 goto out; 3243 3244 #if 0 3245 /* What error should we return now? EUNATTACH? */ 3246 if (pkt_sk(sk)->ifindex < 0) 3247 return -ENODEV; 3248 #endif 3249 3250 if (flags & MSG_ERRQUEUE) { 3251 err = sock_recv_errqueue(sk, msg, len, 3252 SOL_PACKET, PACKET_TX_TIMESTAMP); 3253 goto out; 3254 } 3255 3256 /* 3257 * Call the generic datagram receiver. This handles all sorts 3258 * of horrible races and re-entrancy so we can forget about it 3259 * in the protocol layers. 3260 * 3261 * Now it will return ENETDOWN, if device have just gone down, 3262 * but then it will block. 3263 */ 3264 3265 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err); 3266 3267 /* 3268 * An error occurred so return it. Because skb_recv_datagram() 3269 * handles the blocking we don't see and worry about blocking 3270 * retries. 3271 */ 3272 3273 if (skb == NULL) 3274 goto out; 3275 3276 if (pkt_sk(sk)->pressure) 3277 packet_rcv_has_room(pkt_sk(sk), NULL); 3278 3279 if (pkt_sk(sk)->has_vnet_hdr) { 3280 err = packet_rcv_vnet(msg, skb, &len); 3281 if (err) 3282 goto out_free; 3283 vnet_hdr_len = sizeof(struct virtio_net_hdr); 3284 } 3285 3286 /* You lose any data beyond the buffer you gave. If it worries 3287 * a user program they can ask the device for its MTU 3288 * anyway. 3289 */ 3290 copied = skb->len; 3291 if (copied > len) { 3292 copied = len; 3293 msg->msg_flags |= MSG_TRUNC; 3294 } 3295 3296 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3297 if (err) 3298 goto out_free; 3299 3300 if (sock->type != SOCK_PACKET) { 3301 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3302 3303 /* Original length was stored in sockaddr_ll fields */ 3304 origlen = PACKET_SKB_CB(skb)->sa.origlen; 3305 sll->sll_family = AF_PACKET; 3306 sll->sll_protocol = skb->protocol; 3307 } 3308 3309 sock_recv_ts_and_drops(msg, sk, skb); 3310 3311 if (msg->msg_name) { 3312 /* If the address length field is there to be filled 3313 * in, we fill it in now. 3314 */ 3315 if (sock->type == SOCK_PACKET) { 3316 __sockaddr_check_size(sizeof(struct sockaddr_pkt)); 3317 msg->msg_namelen = sizeof(struct sockaddr_pkt); 3318 } else { 3319 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; 3320 3321 msg->msg_namelen = sll->sll_halen + 3322 offsetof(struct sockaddr_ll, sll_addr); 3323 } 3324 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, 3325 msg->msg_namelen); 3326 } 3327 3328 if (pkt_sk(sk)->auxdata) { 3329 struct tpacket_auxdata aux; 3330 3331 aux.tp_status = TP_STATUS_USER; 3332 if (skb->ip_summed == CHECKSUM_PARTIAL) 3333 aux.tp_status |= TP_STATUS_CSUMNOTREADY; 3334 else if (skb->pkt_type != PACKET_OUTGOING && 3335 (skb->ip_summed == CHECKSUM_COMPLETE || 3336 skb_csum_unnecessary(skb))) 3337 aux.tp_status |= TP_STATUS_CSUM_VALID; 3338 3339 aux.tp_len = origlen; 3340 aux.tp_snaplen = skb->len; 3341 aux.tp_mac = 0; 3342 aux.tp_net = skb_network_offset(skb); 3343 if (skb_vlan_tag_present(skb)) { 3344 aux.tp_vlan_tci = skb_vlan_tag_get(skb); 3345 aux.tp_vlan_tpid = ntohs(skb->vlan_proto); 3346 aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; 3347 } else { 3348 aux.tp_vlan_tci = 0; 3349 aux.tp_vlan_tpid = 0; 3350 } 3351 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); 3352 } 3353 3354 /* 3355 * Free or return the buffer as appropriate. Again this 3356 * hides all the races and re-entrancy issues from us. 3357 */ 3358 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); 3359 3360 out_free: 3361 skb_free_datagram(sk, skb); 3362 out: 3363 return err; 3364 } 3365 3366 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, 3367 int *uaddr_len, int peer) 3368 { 3369 struct net_device *dev; 3370 struct sock *sk = sock->sk; 3371 3372 if (peer) 3373 return -EOPNOTSUPP; 3374 3375 uaddr->sa_family = AF_PACKET; 3376 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); 3377 rcu_read_lock(); 3378 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); 3379 if (dev) 3380 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); 3381 rcu_read_unlock(); 3382 *uaddr_len = sizeof(*uaddr); 3383 3384 return 0; 3385 } 3386 3387 static int packet_getname(struct socket *sock, struct sockaddr *uaddr, 3388 int *uaddr_len, int peer) 3389 { 3390 struct net_device *dev; 3391 struct sock *sk = sock->sk; 3392 struct packet_sock *po = pkt_sk(sk); 3393 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); 3394 3395 if (peer) 3396 return -EOPNOTSUPP; 3397 3398 sll->sll_family = AF_PACKET; 3399 sll->sll_ifindex = po->ifindex; 3400 sll->sll_protocol = po->num; 3401 sll->sll_pkttype = 0; 3402 rcu_read_lock(); 3403 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); 3404 if (dev) { 3405 sll->sll_hatype = dev->type; 3406 sll->sll_halen = dev->addr_len; 3407 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); 3408 } else { 3409 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ 3410 sll->sll_halen = 0; 3411 } 3412 rcu_read_unlock(); 3413 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; 3414 3415 return 0; 3416 } 3417 3418 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, 3419 int what) 3420 { 3421 switch (i->type) { 3422 case PACKET_MR_MULTICAST: 3423 if (i->alen != dev->addr_len) 3424 return -EINVAL; 3425 if (what > 0) 3426 return dev_mc_add(dev, i->addr); 3427 else 3428 return dev_mc_del(dev, i->addr); 3429 break; 3430 case PACKET_MR_PROMISC: 3431 return dev_set_promiscuity(dev, what); 3432 case PACKET_MR_ALLMULTI: 3433 return dev_set_allmulti(dev, what); 3434 case PACKET_MR_UNICAST: 3435 if (i->alen != dev->addr_len) 3436 return -EINVAL; 3437 if (what > 0) 3438 return dev_uc_add(dev, i->addr); 3439 else 3440 return dev_uc_del(dev, i->addr); 3441 break; 3442 default: 3443 break; 3444 } 3445 return 0; 3446 } 3447 3448 static void packet_dev_mclist_delete(struct net_device *dev, 3449 struct packet_mclist **mlp) 3450 { 3451 struct packet_mclist *ml; 3452 3453 while ((ml = *mlp) != NULL) { 3454 if (ml->ifindex == dev->ifindex) { 3455 packet_dev_mc(dev, ml, -1); 3456 *mlp = ml->next; 3457 kfree(ml); 3458 } else 3459 mlp = &ml->next; 3460 } 3461 } 3462 3463 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) 3464 { 3465 struct packet_sock *po = pkt_sk(sk); 3466 struct packet_mclist *ml, *i; 3467 struct net_device *dev; 3468 int err; 3469 3470 rtnl_lock(); 3471 3472 err = -ENODEV; 3473 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); 3474 if (!dev) 3475 goto done; 3476 3477 err = -EINVAL; 3478 if (mreq->mr_alen > dev->addr_len) 3479 goto done; 3480 3481 err = -ENOBUFS; 3482 i = kmalloc(sizeof(*i), GFP_KERNEL); 3483 if (i == NULL) 3484 goto done; 3485 3486 err = 0; 3487 for (ml = po->mclist; ml; ml = ml->next) { 3488 if (ml->ifindex == mreq->mr_ifindex && 3489 ml->type == mreq->mr_type && 3490 ml->alen == mreq->mr_alen && 3491 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3492 ml->count++; 3493 /* Free the new element ... */ 3494 kfree(i); 3495 goto done; 3496 } 3497 } 3498 3499 i->type = mreq->mr_type; 3500 i->ifindex = mreq->mr_ifindex; 3501 i->alen = mreq->mr_alen; 3502 memcpy(i->addr, mreq->mr_address, i->alen); 3503 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); 3504 i->count = 1; 3505 i->next = po->mclist; 3506 po->mclist = i; 3507 err = packet_dev_mc(dev, i, 1); 3508 if (err) { 3509 po->mclist = i->next; 3510 kfree(i); 3511 } 3512 3513 done: 3514 rtnl_unlock(); 3515 return err; 3516 } 3517 3518 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) 3519 { 3520 struct packet_mclist *ml, **mlp; 3521 3522 rtnl_lock(); 3523 3524 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { 3525 if (ml->ifindex == mreq->mr_ifindex && 3526 ml->type == mreq->mr_type && 3527 ml->alen == mreq->mr_alen && 3528 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { 3529 if (--ml->count == 0) { 3530 struct net_device *dev; 3531 *mlp = ml->next; 3532 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3533 if (dev) 3534 packet_dev_mc(dev, ml, -1); 3535 kfree(ml); 3536 } 3537 break; 3538 } 3539 } 3540 rtnl_unlock(); 3541 return 0; 3542 } 3543 3544 static void packet_flush_mclist(struct sock *sk) 3545 { 3546 struct packet_sock *po = pkt_sk(sk); 3547 struct packet_mclist *ml; 3548 3549 if (!po->mclist) 3550 return; 3551 3552 rtnl_lock(); 3553 while ((ml = po->mclist) != NULL) { 3554 struct net_device *dev; 3555 3556 po->mclist = ml->next; 3557 dev = __dev_get_by_index(sock_net(sk), ml->ifindex); 3558 if (dev != NULL) 3559 packet_dev_mc(dev, ml, -1); 3560 kfree(ml); 3561 } 3562 rtnl_unlock(); 3563 } 3564 3565 static int 3566 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) 3567 { 3568 struct sock *sk = sock->sk; 3569 struct packet_sock *po = pkt_sk(sk); 3570 int ret; 3571 3572 if (level != SOL_PACKET) 3573 return -ENOPROTOOPT; 3574 3575 switch (optname) { 3576 case PACKET_ADD_MEMBERSHIP: 3577 case PACKET_DROP_MEMBERSHIP: 3578 { 3579 struct packet_mreq_max mreq; 3580 int len = optlen; 3581 memset(&mreq, 0, sizeof(mreq)); 3582 if (len < sizeof(struct packet_mreq)) 3583 return -EINVAL; 3584 if (len > sizeof(mreq)) 3585 len = sizeof(mreq); 3586 if (copy_from_user(&mreq, optval, len)) 3587 return -EFAULT; 3588 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) 3589 return -EINVAL; 3590 if (optname == PACKET_ADD_MEMBERSHIP) 3591 ret = packet_mc_add(sk, &mreq); 3592 else 3593 ret = packet_mc_drop(sk, &mreq); 3594 return ret; 3595 } 3596 3597 case PACKET_RX_RING: 3598 case PACKET_TX_RING: 3599 { 3600 union tpacket_req_u req_u; 3601 int len; 3602 3603 switch (po->tp_version) { 3604 case TPACKET_V1: 3605 case TPACKET_V2: 3606 len = sizeof(req_u.req); 3607 break; 3608 case TPACKET_V3: 3609 default: 3610 len = sizeof(req_u.req3); 3611 break; 3612 } 3613 if (optlen < len) 3614 return -EINVAL; 3615 if (copy_from_user(&req_u.req, optval, len)) 3616 return -EFAULT; 3617 return packet_set_ring(sk, &req_u, 0, 3618 optname == PACKET_TX_RING); 3619 } 3620 case PACKET_COPY_THRESH: 3621 { 3622 int val; 3623 3624 if (optlen != sizeof(val)) 3625 return -EINVAL; 3626 if (copy_from_user(&val, optval, sizeof(val))) 3627 return -EFAULT; 3628 3629 pkt_sk(sk)->copy_thresh = val; 3630 return 0; 3631 } 3632 case PACKET_VERSION: 3633 { 3634 int val; 3635 3636 if (optlen != sizeof(val)) 3637 return -EINVAL; 3638 if (copy_from_user(&val, optval, sizeof(val))) 3639 return -EFAULT; 3640 switch (val) { 3641 case TPACKET_V1: 3642 case TPACKET_V2: 3643 case TPACKET_V3: 3644 break; 3645 default: 3646 return -EINVAL; 3647 } 3648 lock_sock(sk); 3649 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { 3650 ret = -EBUSY; 3651 } else { 3652 po->tp_version = val; 3653 ret = 0; 3654 } 3655 release_sock(sk); 3656 return ret; 3657 } 3658 case PACKET_RESERVE: 3659 { 3660 unsigned int val; 3661 3662 if (optlen != sizeof(val)) 3663 return -EINVAL; 3664 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3665 return -EBUSY; 3666 if (copy_from_user(&val, optval, sizeof(val))) 3667 return -EFAULT; 3668 po->tp_reserve = val; 3669 return 0; 3670 } 3671 case PACKET_LOSS: 3672 { 3673 unsigned int val; 3674 3675 if (optlen != sizeof(val)) 3676 return -EINVAL; 3677 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3678 return -EBUSY; 3679 if (copy_from_user(&val, optval, sizeof(val))) 3680 return -EFAULT; 3681 po->tp_loss = !!val; 3682 return 0; 3683 } 3684 case PACKET_AUXDATA: 3685 { 3686 int val; 3687 3688 if (optlen < sizeof(val)) 3689 return -EINVAL; 3690 if (copy_from_user(&val, optval, sizeof(val))) 3691 return -EFAULT; 3692 3693 po->auxdata = !!val; 3694 return 0; 3695 } 3696 case PACKET_ORIGDEV: 3697 { 3698 int val; 3699 3700 if (optlen < sizeof(val)) 3701 return -EINVAL; 3702 if (copy_from_user(&val, optval, sizeof(val))) 3703 return -EFAULT; 3704 3705 po->origdev = !!val; 3706 return 0; 3707 } 3708 case PACKET_VNET_HDR: 3709 { 3710 int val; 3711 3712 if (sock->type != SOCK_RAW) 3713 return -EINVAL; 3714 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3715 return -EBUSY; 3716 if (optlen < sizeof(val)) 3717 return -EINVAL; 3718 if (copy_from_user(&val, optval, sizeof(val))) 3719 return -EFAULT; 3720 3721 po->has_vnet_hdr = !!val; 3722 return 0; 3723 } 3724 case PACKET_TIMESTAMP: 3725 { 3726 int val; 3727 3728 if (optlen != sizeof(val)) 3729 return -EINVAL; 3730 if (copy_from_user(&val, optval, sizeof(val))) 3731 return -EFAULT; 3732 3733 po->tp_tstamp = val; 3734 return 0; 3735 } 3736 case PACKET_FANOUT: 3737 { 3738 int val; 3739 3740 if (optlen != sizeof(val)) 3741 return -EINVAL; 3742 if (copy_from_user(&val, optval, sizeof(val))) 3743 return -EFAULT; 3744 3745 return fanout_add(sk, val & 0xffff, val >> 16); 3746 } 3747 case PACKET_FANOUT_DATA: 3748 { 3749 if (!po->fanout) 3750 return -EINVAL; 3751 3752 return fanout_set_data(po, optval, optlen); 3753 } 3754 case PACKET_TX_HAS_OFF: 3755 { 3756 unsigned int val; 3757 3758 if (optlen != sizeof(val)) 3759 return -EINVAL; 3760 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) 3761 return -EBUSY; 3762 if (copy_from_user(&val, optval, sizeof(val))) 3763 return -EFAULT; 3764 po->tp_tx_has_off = !!val; 3765 return 0; 3766 } 3767 case PACKET_QDISC_BYPASS: 3768 { 3769 int val; 3770 3771 if (optlen != sizeof(val)) 3772 return -EINVAL; 3773 if (copy_from_user(&val, optval, sizeof(val))) 3774 return -EFAULT; 3775 3776 po->xmit = val ? packet_direct_xmit : dev_queue_xmit; 3777 return 0; 3778 } 3779 default: 3780 return -ENOPROTOOPT; 3781 } 3782 } 3783 3784 static int packet_getsockopt(struct socket *sock, int level, int optname, 3785 char __user *optval, int __user *optlen) 3786 { 3787 int len; 3788 int val, lv = sizeof(val); 3789 struct sock *sk = sock->sk; 3790 struct packet_sock *po = pkt_sk(sk); 3791 void *data = &val; 3792 union tpacket_stats_u st; 3793 struct tpacket_rollover_stats rstats; 3794 3795 if (level != SOL_PACKET) 3796 return -ENOPROTOOPT; 3797 3798 if (get_user(len, optlen)) 3799 return -EFAULT; 3800 3801 if (len < 0) 3802 return -EINVAL; 3803 3804 switch (optname) { 3805 case PACKET_STATISTICS: 3806 spin_lock_bh(&sk->sk_receive_queue.lock); 3807 memcpy(&st, &po->stats, sizeof(st)); 3808 memset(&po->stats, 0, sizeof(po->stats)); 3809 spin_unlock_bh(&sk->sk_receive_queue.lock); 3810 3811 if (po->tp_version == TPACKET_V3) { 3812 lv = sizeof(struct tpacket_stats_v3); 3813 st.stats3.tp_packets += st.stats3.tp_drops; 3814 data = &st.stats3; 3815 } else { 3816 lv = sizeof(struct tpacket_stats); 3817 st.stats1.tp_packets += st.stats1.tp_drops; 3818 data = &st.stats1; 3819 } 3820 3821 break; 3822 case PACKET_AUXDATA: 3823 val = po->auxdata; 3824 break; 3825 case PACKET_ORIGDEV: 3826 val = po->origdev; 3827 break; 3828 case PACKET_VNET_HDR: 3829 val = po->has_vnet_hdr; 3830 break; 3831 case PACKET_VERSION: 3832 val = po->tp_version; 3833 break; 3834 case PACKET_HDRLEN: 3835 if (len > sizeof(int)) 3836 len = sizeof(int); 3837 if (copy_from_user(&val, optval, len)) 3838 return -EFAULT; 3839 switch (val) { 3840 case TPACKET_V1: 3841 val = sizeof(struct tpacket_hdr); 3842 break; 3843 case TPACKET_V2: 3844 val = sizeof(struct tpacket2_hdr); 3845 break; 3846 case TPACKET_V3: 3847 val = sizeof(struct tpacket3_hdr); 3848 break; 3849 default: 3850 return -EINVAL; 3851 } 3852 break; 3853 case PACKET_RESERVE: 3854 val = po->tp_reserve; 3855 break; 3856 case PACKET_LOSS: 3857 val = po->tp_loss; 3858 break; 3859 case PACKET_TIMESTAMP: 3860 val = po->tp_tstamp; 3861 break; 3862 case PACKET_FANOUT: 3863 val = (po->fanout ? 3864 ((u32)po->fanout->id | 3865 ((u32)po->fanout->type << 16) | 3866 ((u32)po->fanout->flags << 24)) : 3867 0); 3868 break; 3869 case PACKET_ROLLOVER_STATS: 3870 if (!po->rollover) 3871 return -EINVAL; 3872 rstats.tp_all = atomic_long_read(&po->rollover->num); 3873 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); 3874 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); 3875 data = &rstats; 3876 lv = sizeof(rstats); 3877 break; 3878 case PACKET_TX_HAS_OFF: 3879 val = po->tp_tx_has_off; 3880 break; 3881 case PACKET_QDISC_BYPASS: 3882 val = packet_use_direct_xmit(po); 3883 break; 3884 default: 3885 return -ENOPROTOOPT; 3886 } 3887 3888 if (len > lv) 3889 len = lv; 3890 if (put_user(len, optlen)) 3891 return -EFAULT; 3892 if (copy_to_user(optval, data, len)) 3893 return -EFAULT; 3894 return 0; 3895 } 3896 3897 3898 #ifdef CONFIG_COMPAT 3899 static int compat_packet_setsockopt(struct socket *sock, int level, int optname, 3900 char __user *optval, unsigned int optlen) 3901 { 3902 struct packet_sock *po = pkt_sk(sock->sk); 3903 3904 if (level != SOL_PACKET) 3905 return -ENOPROTOOPT; 3906 3907 if (optname == PACKET_FANOUT_DATA && 3908 po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) { 3909 optval = (char __user *)get_compat_bpf_fprog(optval); 3910 if (!optval) 3911 return -EFAULT; 3912 optlen = sizeof(struct sock_fprog); 3913 } 3914 3915 return packet_setsockopt(sock, level, optname, optval, optlen); 3916 } 3917 #endif 3918 3919 static int packet_notifier(struct notifier_block *this, 3920 unsigned long msg, void *ptr) 3921 { 3922 struct sock *sk; 3923 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3924 struct net *net = dev_net(dev); 3925 3926 rcu_read_lock(); 3927 sk_for_each_rcu(sk, &net->packet.sklist) { 3928 struct packet_sock *po = pkt_sk(sk); 3929 3930 switch (msg) { 3931 case NETDEV_UNREGISTER: 3932 if (po->mclist) 3933 packet_dev_mclist_delete(dev, &po->mclist); 3934 /* fallthrough */ 3935 3936 case NETDEV_DOWN: 3937 if (dev->ifindex == po->ifindex) { 3938 spin_lock(&po->bind_lock); 3939 if (po->running) { 3940 __unregister_prot_hook(sk, false); 3941 sk->sk_err = ENETDOWN; 3942 if (!sock_flag(sk, SOCK_DEAD)) 3943 sk->sk_error_report(sk); 3944 } 3945 if (msg == NETDEV_UNREGISTER) { 3946 packet_cached_dev_reset(po); 3947 po->ifindex = -1; 3948 if (po->prot_hook.dev) 3949 dev_put(po->prot_hook.dev); 3950 po->prot_hook.dev = NULL; 3951 } 3952 spin_unlock(&po->bind_lock); 3953 } 3954 break; 3955 case NETDEV_UP: 3956 if (dev->ifindex == po->ifindex) { 3957 spin_lock(&po->bind_lock); 3958 if (po->num) 3959 register_prot_hook(sk); 3960 spin_unlock(&po->bind_lock); 3961 } 3962 break; 3963 } 3964 } 3965 rcu_read_unlock(); 3966 return NOTIFY_DONE; 3967 } 3968 3969 3970 static int packet_ioctl(struct socket *sock, unsigned int cmd, 3971 unsigned long arg) 3972 { 3973 struct sock *sk = sock->sk; 3974 3975 switch (cmd) { 3976 case SIOCOUTQ: 3977 { 3978 int amount = sk_wmem_alloc_get(sk); 3979 3980 return put_user(amount, (int __user *)arg); 3981 } 3982 case SIOCINQ: 3983 { 3984 struct sk_buff *skb; 3985 int amount = 0; 3986 3987 spin_lock_bh(&sk->sk_receive_queue.lock); 3988 skb = skb_peek(&sk->sk_receive_queue); 3989 if (skb) 3990 amount = skb->len; 3991 spin_unlock_bh(&sk->sk_receive_queue.lock); 3992 return put_user(amount, (int __user *)arg); 3993 } 3994 case SIOCGSTAMP: 3995 return sock_get_timestamp(sk, (struct timeval __user *)arg); 3996 case SIOCGSTAMPNS: 3997 return sock_get_timestampns(sk, (struct timespec __user *)arg); 3998 3999 #ifdef CONFIG_INET 4000 case SIOCADDRT: 4001 case SIOCDELRT: 4002 case SIOCDARP: 4003 case SIOCGARP: 4004 case SIOCSARP: 4005 case SIOCGIFADDR: 4006 case SIOCSIFADDR: 4007 case SIOCGIFBRDADDR: 4008 case SIOCSIFBRDADDR: 4009 case SIOCGIFNETMASK: 4010 case SIOCSIFNETMASK: 4011 case SIOCGIFDSTADDR: 4012 case SIOCSIFDSTADDR: 4013 case SIOCSIFFLAGS: 4014 return inet_dgram_ops.ioctl(sock, cmd, arg); 4015 #endif 4016 4017 default: 4018 return -ENOIOCTLCMD; 4019 } 4020 return 0; 4021 } 4022 4023 static unsigned int packet_poll(struct file *file, struct socket *sock, 4024 poll_table *wait) 4025 { 4026 struct sock *sk = sock->sk; 4027 struct packet_sock *po = pkt_sk(sk); 4028 unsigned int mask = datagram_poll(file, sock, wait); 4029 4030 spin_lock_bh(&sk->sk_receive_queue.lock); 4031 if (po->rx_ring.pg_vec) { 4032 if (!packet_previous_rx_frame(po, &po->rx_ring, 4033 TP_STATUS_KERNEL)) 4034 mask |= POLLIN | POLLRDNORM; 4035 } 4036 if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) 4037 po->pressure = 0; 4038 spin_unlock_bh(&sk->sk_receive_queue.lock); 4039 spin_lock_bh(&sk->sk_write_queue.lock); 4040 if (po->tx_ring.pg_vec) { 4041 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) 4042 mask |= POLLOUT | POLLWRNORM; 4043 } 4044 spin_unlock_bh(&sk->sk_write_queue.lock); 4045 return mask; 4046 } 4047 4048 4049 /* Dirty? Well, I still did not learn better way to account 4050 * for user mmaps. 4051 */ 4052 4053 static void packet_mm_open(struct vm_area_struct *vma) 4054 { 4055 struct file *file = vma->vm_file; 4056 struct socket *sock = file->private_data; 4057 struct sock *sk = sock->sk; 4058 4059 if (sk) 4060 atomic_inc(&pkt_sk(sk)->mapped); 4061 } 4062 4063 static void packet_mm_close(struct vm_area_struct *vma) 4064 { 4065 struct file *file = vma->vm_file; 4066 struct socket *sock = file->private_data; 4067 struct sock *sk = sock->sk; 4068 4069 if (sk) 4070 atomic_dec(&pkt_sk(sk)->mapped); 4071 } 4072 4073 static const struct vm_operations_struct packet_mmap_ops = { 4074 .open = packet_mm_open, 4075 .close = packet_mm_close, 4076 }; 4077 4078 static void free_pg_vec(struct pgv *pg_vec, unsigned int order, 4079 unsigned int len) 4080 { 4081 int i; 4082 4083 for (i = 0; i < len; i++) { 4084 if (likely(pg_vec[i].buffer)) { 4085 if (is_vmalloc_addr(pg_vec[i].buffer)) 4086 vfree(pg_vec[i].buffer); 4087 else 4088 free_pages((unsigned long)pg_vec[i].buffer, 4089 order); 4090 pg_vec[i].buffer = NULL; 4091 } 4092 } 4093 kfree(pg_vec); 4094 } 4095 4096 static char *alloc_one_pg_vec_page(unsigned long order) 4097 { 4098 char *buffer; 4099 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | 4100 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; 4101 4102 buffer = (char *) __get_free_pages(gfp_flags, order); 4103 if (buffer) 4104 return buffer; 4105 4106 /* __get_free_pages failed, fall back to vmalloc */ 4107 buffer = vzalloc((1 << order) * PAGE_SIZE); 4108 if (buffer) 4109 return buffer; 4110 4111 /* vmalloc failed, lets dig into swap here */ 4112 gfp_flags &= ~__GFP_NORETRY; 4113 buffer = (char *) __get_free_pages(gfp_flags, order); 4114 if (buffer) 4115 return buffer; 4116 4117 /* complete and utter failure */ 4118 return NULL; 4119 } 4120 4121 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) 4122 { 4123 unsigned int block_nr = req->tp_block_nr; 4124 struct pgv *pg_vec; 4125 int i; 4126 4127 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL); 4128 if (unlikely(!pg_vec)) 4129 goto out; 4130 4131 for (i = 0; i < block_nr; i++) { 4132 pg_vec[i].buffer = alloc_one_pg_vec_page(order); 4133 if (unlikely(!pg_vec[i].buffer)) 4134 goto out_free_pgvec; 4135 } 4136 4137 out: 4138 return pg_vec; 4139 4140 out_free_pgvec: 4141 free_pg_vec(pg_vec, order, block_nr); 4142 pg_vec = NULL; 4143 goto out; 4144 } 4145 4146 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, 4147 int closing, int tx_ring) 4148 { 4149 struct pgv *pg_vec = NULL; 4150 struct packet_sock *po = pkt_sk(sk); 4151 int was_running, order = 0; 4152 struct packet_ring_buffer *rb; 4153 struct sk_buff_head *rb_queue; 4154 __be16 num; 4155 int err = -EINVAL; 4156 /* Added to avoid minimal code churn */ 4157 struct tpacket_req *req = &req_u->req; 4158 4159 lock_sock(sk); 4160 4161 rb = tx_ring ? &po->tx_ring : &po->rx_ring; 4162 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; 4163 4164 err = -EBUSY; 4165 if (!closing) { 4166 if (atomic_read(&po->mapped)) 4167 goto out; 4168 if (packet_read_pending(rb)) 4169 goto out; 4170 } 4171 4172 if (req->tp_block_nr) { 4173 /* Sanity tests and some calculations */ 4174 err = -EBUSY; 4175 if (unlikely(rb->pg_vec)) 4176 goto out; 4177 4178 switch (po->tp_version) { 4179 case TPACKET_V1: 4180 po->tp_hdrlen = TPACKET_HDRLEN; 4181 break; 4182 case TPACKET_V2: 4183 po->tp_hdrlen = TPACKET2_HDRLEN; 4184 break; 4185 case TPACKET_V3: 4186 po->tp_hdrlen = TPACKET3_HDRLEN; 4187 break; 4188 } 4189 4190 err = -EINVAL; 4191 if (unlikely((int)req->tp_block_size <= 0)) 4192 goto out; 4193 if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) 4194 goto out; 4195 if (po->tp_version >= TPACKET_V3 && 4196 (int)(req->tp_block_size - 4197 BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0) 4198 goto out; 4199 if (unlikely(req->tp_frame_size < po->tp_hdrlen + 4200 po->tp_reserve)) 4201 goto out; 4202 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) 4203 goto out; 4204 4205 rb->frames_per_block = req->tp_block_size / req->tp_frame_size; 4206 if (unlikely(rb->frames_per_block == 0)) 4207 goto out; 4208 if (unlikely((rb->frames_per_block * req->tp_block_nr) != 4209 req->tp_frame_nr)) 4210 goto out; 4211 4212 err = -ENOMEM; 4213 order = get_order(req->tp_block_size); 4214 pg_vec = alloc_pg_vec(req, order); 4215 if (unlikely(!pg_vec)) 4216 goto out; 4217 switch (po->tp_version) { 4218 case TPACKET_V3: 4219 /* Block transmit is not supported yet */ 4220 if (!tx_ring) { 4221 init_prb_bdqc(po, rb, pg_vec, req_u); 4222 } else { 4223 struct tpacket_req3 *req3 = &req_u->req3; 4224 4225 if (req3->tp_retire_blk_tov || 4226 req3->tp_sizeof_priv || 4227 req3->tp_feature_req_word) { 4228 err = -EINVAL; 4229 goto out; 4230 } 4231 } 4232 break; 4233 default: 4234 break; 4235 } 4236 } 4237 /* Done */ 4238 else { 4239 err = -EINVAL; 4240 if (unlikely(req->tp_frame_nr)) 4241 goto out; 4242 } 4243 4244 4245 /* Detach socket from network */ 4246 spin_lock(&po->bind_lock); 4247 was_running = po->running; 4248 num = po->num; 4249 if (was_running) { 4250 po->num = 0; 4251 __unregister_prot_hook(sk, false); 4252 } 4253 spin_unlock(&po->bind_lock); 4254 4255 synchronize_net(); 4256 4257 err = -EBUSY; 4258 mutex_lock(&po->pg_vec_lock); 4259 if (closing || atomic_read(&po->mapped) == 0) { 4260 err = 0; 4261 spin_lock_bh(&rb_queue->lock); 4262 swap(rb->pg_vec, pg_vec); 4263 rb->frame_max = (req->tp_frame_nr - 1); 4264 rb->head = 0; 4265 rb->frame_size = req->tp_frame_size; 4266 spin_unlock_bh(&rb_queue->lock); 4267 4268 swap(rb->pg_vec_order, order); 4269 swap(rb->pg_vec_len, req->tp_block_nr); 4270 4271 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; 4272 po->prot_hook.func = (po->rx_ring.pg_vec) ? 4273 tpacket_rcv : packet_rcv; 4274 skb_queue_purge(rb_queue); 4275 if (atomic_read(&po->mapped)) 4276 pr_err("packet_mmap: vma is busy: %d\n", 4277 atomic_read(&po->mapped)); 4278 } 4279 mutex_unlock(&po->pg_vec_lock); 4280 4281 spin_lock(&po->bind_lock); 4282 if (was_running) { 4283 po->num = num; 4284 register_prot_hook(sk); 4285 } 4286 spin_unlock(&po->bind_lock); 4287 if (closing && (po->tp_version > TPACKET_V2)) { 4288 /* Because we don't support block-based V3 on tx-ring */ 4289 if (!tx_ring) 4290 prb_shutdown_retire_blk_timer(po, rb_queue); 4291 } 4292 4293 if (pg_vec) 4294 free_pg_vec(pg_vec, order, req->tp_block_nr); 4295 out: 4296 release_sock(sk); 4297 return err; 4298 } 4299 4300 static int packet_mmap(struct file *file, struct socket *sock, 4301 struct vm_area_struct *vma) 4302 { 4303 struct sock *sk = sock->sk; 4304 struct packet_sock *po = pkt_sk(sk); 4305 unsigned long size, expected_size; 4306 struct packet_ring_buffer *rb; 4307 unsigned long start; 4308 int err = -EINVAL; 4309 int i; 4310 4311 if (vma->vm_pgoff) 4312 return -EINVAL; 4313 4314 mutex_lock(&po->pg_vec_lock); 4315 4316 expected_size = 0; 4317 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4318 if (rb->pg_vec) { 4319 expected_size += rb->pg_vec_len 4320 * rb->pg_vec_pages 4321 * PAGE_SIZE; 4322 } 4323 } 4324 4325 if (expected_size == 0) 4326 goto out; 4327 4328 size = vma->vm_end - vma->vm_start; 4329 if (size != expected_size) 4330 goto out; 4331 4332 start = vma->vm_start; 4333 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { 4334 if (rb->pg_vec == NULL) 4335 continue; 4336 4337 for (i = 0; i < rb->pg_vec_len; i++) { 4338 struct page *page; 4339 void *kaddr = rb->pg_vec[i].buffer; 4340 int pg_num; 4341 4342 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { 4343 page = pgv_to_page(kaddr); 4344 err = vm_insert_page(vma, start, page); 4345 if (unlikely(err)) 4346 goto out; 4347 start += PAGE_SIZE; 4348 kaddr += PAGE_SIZE; 4349 } 4350 } 4351 } 4352 4353 atomic_inc(&po->mapped); 4354 vma->vm_ops = &packet_mmap_ops; 4355 err = 0; 4356 4357 out: 4358 mutex_unlock(&po->pg_vec_lock); 4359 return err; 4360 } 4361 4362 static const struct proto_ops packet_ops_spkt = { 4363 .family = PF_PACKET, 4364 .owner = THIS_MODULE, 4365 .release = packet_release, 4366 .bind = packet_bind_spkt, 4367 .connect = sock_no_connect, 4368 .socketpair = sock_no_socketpair, 4369 .accept = sock_no_accept, 4370 .getname = packet_getname_spkt, 4371 .poll = datagram_poll, 4372 .ioctl = packet_ioctl, 4373 .listen = sock_no_listen, 4374 .shutdown = sock_no_shutdown, 4375 .setsockopt = sock_no_setsockopt, 4376 .getsockopt = sock_no_getsockopt, 4377 .sendmsg = packet_sendmsg_spkt, 4378 .recvmsg = packet_recvmsg, 4379 .mmap = sock_no_mmap, 4380 .sendpage = sock_no_sendpage, 4381 }; 4382 4383 static const struct proto_ops packet_ops = { 4384 .family = PF_PACKET, 4385 .owner = THIS_MODULE, 4386 .release = packet_release, 4387 .bind = packet_bind, 4388 .connect = sock_no_connect, 4389 .socketpair = sock_no_socketpair, 4390 .accept = sock_no_accept, 4391 .getname = packet_getname, 4392 .poll = packet_poll, 4393 .ioctl = packet_ioctl, 4394 .listen = sock_no_listen, 4395 .shutdown = sock_no_shutdown, 4396 .setsockopt = packet_setsockopt, 4397 .getsockopt = packet_getsockopt, 4398 #ifdef CONFIG_COMPAT 4399 .compat_setsockopt = compat_packet_setsockopt, 4400 #endif 4401 .sendmsg = packet_sendmsg, 4402 .recvmsg = packet_recvmsg, 4403 .mmap = packet_mmap, 4404 .sendpage = sock_no_sendpage, 4405 }; 4406 4407 static const struct net_proto_family packet_family_ops = { 4408 .family = PF_PACKET, 4409 .create = packet_create, 4410 .owner = THIS_MODULE, 4411 }; 4412 4413 static struct notifier_block packet_netdev_notifier = { 4414 .notifier_call = packet_notifier, 4415 }; 4416 4417 #ifdef CONFIG_PROC_FS 4418 4419 static void *packet_seq_start(struct seq_file *seq, loff_t *pos) 4420 __acquires(RCU) 4421 { 4422 struct net *net = seq_file_net(seq); 4423 4424 rcu_read_lock(); 4425 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); 4426 } 4427 4428 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) 4429 { 4430 struct net *net = seq_file_net(seq); 4431 return seq_hlist_next_rcu(v, &net->packet.sklist, pos); 4432 } 4433 4434 static void packet_seq_stop(struct seq_file *seq, void *v) 4435 __releases(RCU) 4436 { 4437 rcu_read_unlock(); 4438 } 4439 4440 static int packet_seq_show(struct seq_file *seq, void *v) 4441 { 4442 if (v == SEQ_START_TOKEN) 4443 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n"); 4444 else { 4445 struct sock *s = sk_entry(v); 4446 const struct packet_sock *po = pkt_sk(s); 4447 4448 seq_printf(seq, 4449 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", 4450 s, 4451 atomic_read(&s->sk_refcnt), 4452 s->sk_type, 4453 ntohs(po->num), 4454 po->ifindex, 4455 po->running, 4456 atomic_read(&s->sk_rmem_alloc), 4457 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), 4458 sock_i_ino(s)); 4459 } 4460 4461 return 0; 4462 } 4463 4464 static const struct seq_operations packet_seq_ops = { 4465 .start = packet_seq_start, 4466 .next = packet_seq_next, 4467 .stop = packet_seq_stop, 4468 .show = packet_seq_show, 4469 }; 4470 4471 static int packet_seq_open(struct inode *inode, struct file *file) 4472 { 4473 return seq_open_net(inode, file, &packet_seq_ops, 4474 sizeof(struct seq_net_private)); 4475 } 4476 4477 static const struct file_operations packet_seq_fops = { 4478 .owner = THIS_MODULE, 4479 .open = packet_seq_open, 4480 .read = seq_read, 4481 .llseek = seq_lseek, 4482 .release = seq_release_net, 4483 }; 4484 4485 #endif 4486 4487 static int __net_init packet_net_init(struct net *net) 4488 { 4489 mutex_init(&net->packet.sklist_lock); 4490 INIT_HLIST_HEAD(&net->packet.sklist); 4491 4492 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops)) 4493 return -ENOMEM; 4494 4495 return 0; 4496 } 4497 4498 static void __net_exit packet_net_exit(struct net *net) 4499 { 4500 remove_proc_entry("packet", net->proc_net); 4501 } 4502 4503 static struct pernet_operations packet_net_ops = { 4504 .init = packet_net_init, 4505 .exit = packet_net_exit, 4506 }; 4507 4508 4509 static void __exit packet_exit(void) 4510 { 4511 unregister_netdevice_notifier(&packet_netdev_notifier); 4512 unregister_pernet_subsys(&packet_net_ops); 4513 sock_unregister(PF_PACKET); 4514 proto_unregister(&packet_proto); 4515 } 4516 4517 static int __init packet_init(void) 4518 { 4519 int rc = proto_register(&packet_proto, 0); 4520 4521 if (rc != 0) 4522 goto out; 4523 4524 sock_register(&packet_family_ops); 4525 register_pernet_subsys(&packet_net_ops); 4526 register_netdevice_notifier(&packet_netdev_notifier); 4527 out: 4528 return rc; 4529 } 4530 4531 module_init(packet_init); 4532 module_exit(packet_exit); 4533 MODULE_LICENSE("GPL"); 4534 MODULE_ALIAS_NETPROTO(PF_PACKET); 4535